y = 5 x Divide both sides by 5
y / 5 = x
x = y / 5
y = 4 x - 4
y = 4 * ( y / 5 ) - 4
y = 4 y / 5 - 4 Subtract 4 y / 5 to both sides
y - 4 y / 5 = 4 y / 5 - 4 - 4 y / 5
y - 4 y / 5 = - 4
5 y / 5 - 4 y / 5 = - 4
y / 5 = - 4 Multiply both sides by 5
y = - 20
x = y / 5
x = - 20 / 5
x = - 4
The solutions are:
x = - 4 and y = - 20
Answer b
Find the solution to the system by the substitution methond.
y=4x-4
y=5x
a.(1,0)
b.(-4,-20)
c.(4,0)
d.(-3,-15)
(Im confused !!!please explain to me how get the answer)!
2 answers
Since it asked for substitution, why not just sub the 2nd into the 1st
5x = 4x - 4
x = -4
now back into the 2nd:
y = 5x= 5(-4) = -20
so the intersection point is (-4,-20)
5x = 4x - 4
x = -4
now back into the 2nd:
y = 5x= 5(-4) = -20
so the intersection point is (-4,-20)