How do i calculate the gradient of the following equations?

Question

4a+3b= 27

and

5a-2b=28

I understand the whole rise/run thing but feel like the answers I got a wrong

Answer 1

1st of all you need to know what's on the x-axis, what's on the y-axis.

Suppose a is x, b is y, then

3b = -4a + 27

b = (-4/3)a + 27

gradient is -4/3

If a is y and b is x, then

4a = -3b + 27

a = (-3/4)b + 27

gradient is -3/4

Answer 2

if x axis is a and y axis is b then first equation is

3b=-4a+27

or b=(4/3)a +27

gradient=(4/3)

for second

-2b=-5a+28

or b= (5/2)a -14

gradient= (5/2)

Answer 3

the gradient will look like this, except the vertical lines are continuous:

|4   3|

|5  -2|

and to calculate it you follow the rule: 4* (-2) - 3*5 = -8-15 = -23.

in general, the rule for calculating :

|a   b|

|c   d|  =  a*d - b*c.