What expression is equivalent to 1/2-(-8)

I’m stuck on this equation, anyone got the answer?

Determine the vertex form of g(x) = x2 + 2x - 1. which graph represents g(x)? -nw -3-2-1, 1 1 2 3 -3 2- 1 -3- 1 2 3 - 1 2 3

A. find the power of the test, when the null hypothesis assumes a population mean of mu = 450, with a population standard deviation of 156, the sample size is 5 and the true mean is 638.47 with confidence intervals of 95 b. find the power of the test, when the null hypothesis assumes a population mean of mu = 644, with a population standard deviation of 174, the sample size is 3 and the true mean is 744.04 with confidence intervals of 95% c. find the power of the test, when the null hypothesis assumes a population mean of mu = 510, with a population standard deviation of 126, the sample size is 10 and the true mean is 529.44 with confidence intervals of 95