There is actually 2 ways to solve this, I will show you both.
The first is obvious, solve for x in the first one, and plug it into the 2nd one and get the answer
4x + 7 = 12
4x = 5
x = 
8() + 3
2 * 5 + 3
10 + 3
13
The 2nd option is to manipulate the 4x + 7 to be 8x + 3
4x + 7 = 12
start by moving the 7 over
4x = 5
multiply both sides by 2
8x = 10
and add 3 to both sides
8x + 3 = 13
4x + 3y = 12
3y = -4x + 12
y = -4/3x + 4........so the slope (or gradient) is -4/3...because in y = mx + b form, the slope(gradient) is in the m position and the y int is in the b position....so if u wanted to know the y axis, it would be (0,4)
the x intercept (where the line crosses the x axis) can be found by subbing in 0 for y in the original equation or the slope intercept equation, and solving for x.
4x + 3(0) = 12
4x = 12
x = 12/4 = 3....so the x intercept is (3,0)
The standard form is 21x-y-7=0
The answer would b be d 8 I think
