4. This system of equations has solution (5, -2):
Find the missing values A and B.

Answer is under this sentence

Step-by-step explanation:

(5,-2) is the solution of the equation, which means that x = 5 and y = -2

so you obtain:

5A + 2B = 24

5B - 2A = 31

Now you need to know either A or B. If we know A, we can also know B and vice-versa.

In order to do that, we get rid of either A or B from our equations. So, we multiply the first equation by -5 and the second one by 2. You'll obtain -10B and +10B in those equations:

-25A - 10B = -120

10B - 4A = 62

If we add up both equations, notice how 10B and -10B cancel each other:

-25A - 4A = -120 + 62

-29A = -58

A = 2

Knowing A, we can know B as well. We go back to our initial equations and we choose the 1st one(or the 2nd one):

5A + 2B = 24

5 * 2 + 2B = 24

2B = 24 - 10

2B = 14

B = 7

So A = 2 and B = 7

Note: I suggest you check in case the arithmetics are done correctly.

step-by-step explanation:

the answer is 24

step-by-step explanation: