Answer:
x = -2
y = 3
Step-by-step explanation:
Write the system the following way:
4x + 5y = 7
-3x +y = 9
we need to eliminate one unknown by multiplying one equation for a suitable number in such a way that when we add the equations one unknown is eliminated.
If we multiply the second eq. by -5 the y is eliminated
4x + 5y = 7
15x -5y = -45
add the equations
19x = -38 ===> x = -38/19 ===> x = -2
Now replace this value in any equation to get y. For example, in 1st one.
4(-2) + 5y = 7 ===> -8 +5y = 7 ===> 5y = 7+8 ===> 5y = 15 ===> y = 15/5 ===>
y=3
