Which system of equations has a solution of approximately (0.7, –1.4)?

50x² + 35x - 49 = 0

Step-by-step explanation:

x = 0.7 or x = -1.4

We have to convert the improper fraction value of the roots. (You can use your calculator to save time)

x = 7/10 or x = - 7/5

x - 7/10 = 0 or x + 7/5 = 0

(x -7/10)(x + 7/5) = 0

multiply through the bracket

x² + (7/5x - 7/10x) - 49/50 = 0

x² + 7/10x - 49/50 = 0

Multiply through by 50 to eliminate the fraction from the equation

50x² + 35x - 49 = 0

50x² + 35x - 49 = 0 is the equation that satisfies the root x = 0.7 or x = -1.4

8(-10x+3.5y-7)

8×-10x + 8×3.5y + 8×-7

-80x + 28y - 56

therefore

-80x+28y-56 is the correct answer