a) Solution (x, y): (2, -6)
b) Solution (x, y): (9, -4)
Step-by-step explanation:
a) y = -3x ...equation 1
x + y = -4 ...equation 2
Using substitution method:
substitute -3x for y in equation 2
x + (-3x) = -4
x - 3x = -4
-2x = -4
x = -4/-2
x =2
substitute for x in equation 1:
y = -3(2)
y = -6
Solution (x, y): (2, -6)
b) -4y - 3x = -11 ...equation 1
x - 2y = 17 ...equation 2
Using substitution method:
make x the subject of formula in equation 2:
x - 2y = 17
x = 17 + 2y
substitute for x in equation 1:
-4y - 3(17 + 2y) = -11
-4y -51 - 6y = -11
-10y - 51 = -11
-10y = -11 + 51
-10y =40
y = 40/-10
y = -4
substitue for y in equation 2
x - 2(-4) = 17
x + 8 = 17
x = 17 - 8
x = 9
Solution (x, y): (9, -4)