18 x 3 + 12 - 1 x 34 + 13 - 2 x 56 = 67
<=Work=>
18 x 3 = 54
1 x 34 = 34
2 x 56 = 112
(54) + 12 - (34) + 13 - (112)
66 - 34 + 13 - 112
32 + 13 - 112
45 - 112
= 67
Measure of angle 2 is 77. hope this helped.
So, we know the sum of the first 17 terms is -170, thus S₁₇ = -170, and we also know the first term is 2, well
well, since the 17th term is that much, let's check what "d" is then anyway,
where are the statements so i can help
So x + y = 45, and 4x + 5y = 195. Get y by itself. Subtract x from both sides in the first equation to get y = 45 -x, and subtract 4x from the second equation to get 5y = 195 - 4x. Divide by 5 to both sides to get y = 39 - 4/5x. 39 - 4/5x = 45 - x. Add x to both sides to get 39 - 1/5x = 45. Subtract 39 from both sides to get -1/5x = 6. Divide by -1/5 to get x = -30, or 30. In the first equation, do 30 + y = 45. Subtract 30 from both sides to get y = 15. Check. 4(30) + 15(5) = 195, or 120 + 75 = 195.
