For perpendicular lines, m1m2 = -1 or m2 = -1/m1; where m1 and m2 are the slopes of the lines.
Here line 1 is 3x - 7y = 42
7y = 3x - 42
y = 3/7 x - 6; Hence m1 = 3/7
m2 = -1/(3/7) = -7/3
Required equation y - y1 = m2(x - x1)
y - (-8) = -7/3(x - (-3))
y + 8 = -7/3(x + 3)
y + 8 = -7/3 x - 7
y = -7/3 x - 7 - 8
y = -7/3 x - 15
Y = -1/2x + 5 is the answer
64 = 2 ^6
16 = 2^4 =
2^ 6*(2x+4) = 2^4 * 5x
6(2x+4) = 20x
10/3 x = 2x +4
4/3 x = 4
x = 3
you can also use logarithms like so
(2x+4)ln64 = 5x ln16
ln64/ln16 = 3/2
3/2 * 2x + 3/2 * 4 = 5x
3x + 6 = 5x
2x = 6
x = 3
