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It is important to learn this process, so that you can apply it to more difficult equations! Solving Two-Step Equations left side Every equation has 2 sides, separated by the = sign. 4 + x = 12 right side The solution to an equation is expressed as an equation with the variable ALONE on one side. The solution is : y = 2 example: y + 3 = 5 We also use INVERSE OPERATIONS. The inverse of multiplication is division. The inverse of division is multiplication. The inverse of subtraction is addition. The inverse of addition is subtraction. Example 1 The inverse of addition is subtraction, so we need to subtract 9 from both sides of the equation. We need to UNDO the 9, which is added to p. p + 9 = 12 p - 9 = - 9 3 You must show the steps of solving your equations in this manner! Example 2 We need to UNDO the 3, which is subtracted from s. The inverse of subtraction is addition, so we need to add 3 to both sides of the equation. s s - 3 = 17 + 3 = + 3 20 You must show the steps of solving your equations! Example 3 The inverse of multiplication is division, so we need to divide both sides of the equation by 5. We need to UNDO the 5, which is multiplied by x. ÷ 5x = 35 x 5 = ÷ 5 7 You must show the steps of solving your equations! We use this same process when more than one number is on the same side of the equation as the variable. However, it is important to remember to use inverse operations to
undo ADDITION or SUBTRACTION BEFORE undoing MULTIPLICATION or DIVISION.
Use inverse operations to undo the constant before undoing the coefficient. Coefficient 4 x + 9 = 21 Constant Example 1 4 x 4x = 12 4 4 + x - 9 9 = = - 9 21 3 solution divide both sides by 4 subtract 9 from both sides Example 2 2p - 3 = 27 2p = 30 2 p = 15 + 3 +3 2 add 3 to both sides solution divide both sides by 2 Make sure you type in the+ addition or - subtractionsign on both sides. SLOW DOWN!! You have to put in answerson the next screen. Your turn! 5y - 15 = 20 Fill in the missing numbers. 5y = 35 y = Type in the + or -sign and the number. Solve these two step equations. 3y + 8 = 23 3y = 15 y = Type in the + or -sign and the number. Solve these two step equations. 4y - 1 = 15 4y = 16 y = Type in the + or -sign and the number. Solve these two step equations. 5y - 4 = 36 5y = 40 y = Type in the + or -sign and the number. Solve these two step equations. y - 1 = 2 5 x y = 5 y = x Type in the + or -sign and the number. Solve these two step equations. y + 14 = 23 3 x y = 3 y = x Type in the + or -sign and the number. Solve these two step equations. y - 9 = 15 4 x y = 4 y = x Type in the + or -sign and the number. Solve these two step equations. 7y - 9 = 54 y = = Type in the + or -sign and the number. Solve these two step equations. 4y + 1 = 33 y = = Type in the + or -sign and the number. Solve these two step equations. 3y - 8 = 22 y = = Type in the + or -sign and the number. Solve these two step equations. 2y + 7 = 17 y = = Type in the + or -sign and the number. Solve these two step equations. 7y + 9 = 44 y = = Type in the + or -sign and the number. |