What is the solution (a, b) to this system of linear equations?

3a+6b=45

2a-2b=-12

Ngrid mixes 3.6 pounds of almonds with some raisins to make a trail mix. she divides the trail mix into 12 equal portions. each portion weighs 0.7 pound. how many pounds of raisins did she use to make the trail mix? express the answer to the nearest tenth.

Atriangle includes one angle that 72º. which pair could be the measures of the other two angles of the triangle? a. 9º, 9º b. 26º, 46º c. 53º, 55º d. 72º, 108º

If the scale factor between two circles is 2x/5y what is the ratio of their areas?