Chapter 9 - Quadratic Functions and Equations - 9-3 Solving Quadratic Equations - Practice and Problem-Solving Exercises - Page 552: 47

y = ± 0.4

7$y^{2}$ + 0.12 = 1.24 First, subtract 0.12 from both sides: 7$y^{2}$ + 0.12 -0.12 = 1.24 - 0.12 7$y^{2}$ = 1.12 Now, divide both sides of the equation by 7 to get $y^{2}$ by itself: 7$y^{2}$ $\div$ 7= 1.12 $\div$ 7 $y^{2}$ = 0.16 Take the square root of both sides: $\sqrt y^{2}$ = $\sqrt 0.16$ y = ±0.4