Question

Find the value of p that makes the linear graph y=p-3x pass through the point where the lines 4x-y=6 and 2x-5y=12

Answer 1

4x - y = 6
4x - 6 = y

2x - 5y = 12
2x - 5(4x - 6) = 12
2x - 20x + 30 = 12
2x - 20x = 12 - 30
-18x = -18
x = -18/-18
x = 1

4x - 6 = y
4(1) - 6 = y
4 - 6 = y
-2 = y

so the 2 lines given intersect at (1,-2)

y = p - 3x......(1,-2)...x = 1 and y = -2
-2 = p - 3(1)
-2 = p - 3
-2 + 3 = p
1 = p <===