Let A represent amount of Type A coffee pounds used.
Let B represent amount of Type B coffee pounds used
A + B = 156
B = 156 - A
A = 156 - B
5.80A + 4.65B = 826.60
580 (156 - B) + 4.65B - 826.60 = 0
904.8 - 5.80B + 4.65B - 826.60 = 0
904.8 - 1.15B - 826.60 = 0
78.2 - 1.15B = 0
78.2/1.15 = 1.15B/1.15
68 = B
B = 68 pounds of Type B coffee
There's many more steps you can take to check and etc but am too lazy to put down sorry.
11. is 25°
(Both triangles have two congruent angles which means the 3rd angle is bound to be the same. Just add the 90° and the 65° to get 155 and subtract from 180° because all triangles equal 180°)
12. is 25°
(Same as before, two of the angles are congruent so the third one is the same. Add all of the angles together and have them equal 180° because their is a variable present. 2x+60+70=180 or 2x+130=180. subtract 130 from both sides to get the equation 2x=50 and then divide both sides by 2 to get x=25.)
13. y=14 and x=11.6 (assuming m<d says 15x ÷ 2 because I couldn't really read it)
(m<a = m<d and m<b = m<e because they are lined up together in the ABC and DEF equation. so 3y=42 and (15x÷2=87)
