Do exactly what it says ...
8X+5Y=-7
8(36-8Y) + 5Y = -7
solve for Y, then sub that back into your second equation.
I am sure you can take it from here
SOLVE BY SUBSTITUTION MATH...8X+5Y=-7
X=36-8Y
2 answers
8X + 5Y = -7
X = 36 - 8Y
Substitute 36 - 8y for x in 1st Eq:
8(36 - 8y) + 5y = -7,
288 - 64y + 5y = -7,
-64y + 5y = -7 -288,
-59y = - 295,
y = -295/-59 = 5.
Substitute 5 for y in the 2nd Eq:
X = 36 - 8 * 5 = -4.
Solution set: (-4 , 5).
X = 36 - 8Y
Substitute 36 - 8y for x in 1st Eq:
8(36 - 8y) + 5y = -7,
288 - 64y + 5y = -7,
-64y + 5y = -7 -288,
-59y = - 295,
y = -295/-59 = 5.
Substitute 5 for y in the 2nd Eq:
X = 36 - 8 * 5 = -4.
Solution set: (-4 , 5).
4 answers