What is the slope of the line graphed below (3,5) (0,-1)

The contents of 3838 cans of coke have a mean of x¯¯¯=12.15x¯=12.15. assume the contents of cans of coke have a normal distribution with standard deviation of σ=0.12.σ=0.12. find the value of the test statistic zz for the claim that the population mean is μ=12.μ=12.

Can someone me and do the problem plz so i can understand it more better

Solve the system of equations y= 3/2 - 1, -x+ y =-3