Solve for x and y in the following pair of equations:
Y = -0.2x + 4.2
X - 0.5y = 10
A) x = 11; y = 2
B) x = 2; y = 11
C) x = 11; y = 6.4
D) x = 6.45; y = 2.9
E) x = 6.4; y = 11

Question

Quizplus · Accepted Answer

To solve for x and y, substitute the first equation into the second. From Y = -0.2x + 4.2, substitute Y in X - 0.5Y = 10, giving X - 0.5(-0.2X + 4.2) = 10. Simplifying, X + 0.1X - 2.1 = 10, leading to 1.1X = 12.1, so X = 11. Substituting X = 11 into Y = -0.2(11) + 4.2 gives Y = 2.

Solve for X and Y in the Following Pair of Equations