If the following system of equations was written as a matrix equation in the form ax = c, and matrix a was expressed in the form [a c b d] , find the value of a - b + c + d.
5x + 7y = 7
3x - 2y = 9

my main problem is understanding which numbers are a, b, c, and d.

let's solve your equation step-by-step.

4x+2=2x+12

step 1: subtract 2x from both sides.

4x+2−2x=2x+12−2x

2x+2=12

step 2: subtract 2 from both sides.

2x+2−2=12−2

2x=10

step 3: divide both sides by 2.

2x

2

=

10

2

x=5

step-by-step explanation:

so far i think you have the right thing going for you just remember soh cah toh

step-by-step explanation:

sine over hypotenuse

cosine   equals adjacent

tangent over hypotenuse