1 + 4 = 5
2 + 5 = 12
3 + 6 = 21
8 + 11 = ?

How do you answer this question? (step by step)

Given the system of equations presented here: 2x + 4y = 14 4x + y = 20 which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated? multiply the second equation by â’4 to get â’16x â’ 4y = â’80 multiply the second equation by â’1 to get â’4x â’ y = â’20 multiply the first equation by 2 to get 4x + 8y = 28 multiply the first equation by â’1 to get â’2x â’ 4y = â’14

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cos of 61.6