20 Points
Find the cofactors of each entry in the first row of the matrix

Arianna is buying plants for her garden. she buys 15 flowering plants for $96. pink flowering plants sell for $8, and purple flowering plants sell for $5. how many pink flowering plants did arianna buy? i figured out the answer! the answer is 7. 8x +5y = 96 plug in 7 for x 8 (7) + 5y = 96 56 + 5y = 96 subtract 56 from both sides 5y/y = 40/5 y = 8 she bought 7 pink and 8 purple plants

For f(x)=2x+3 and g(x)=x^2- 8 find (f+g) (x)

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.