170k views
5 votes
-9.3x+8.6y=45.1
7.1x+1.7y=-17.9
What is x and y?

1 Answer

2 votes

Answer:

(x, y) = (-3, 2)

Explanation:

For equations that involve tedious math, I like to let a graphing calculator do it. The solution is ...

(x, y) = (-3, 2)

_____

Fully equivalent to solution by elimination is the use of Cramer's rule. It tells you ...

Δ = (-9.3)(1.7) -(7.1)(8.6) = -76.87

x = ((45.1)(1.7) -(-17.9)(8.6)) / Δ = 230.61/-76.87 = -3

y = ((-9.3)(-17.9) -(7.1)(45.1)) / Δ = -153.74/-76.87 = 2

The solution is (x, y) = (-3, 2).

-9.3x+8.6y=45.1 7.1x+1.7y=-17.9 What is x and y?-example-1
User ZiNNED
by
7.1k points