exam Maths Puzzle Numerical Ability

Can someone answer this one for me?

Use the Distributive Property to remove the parentheses from the following expression:

(1 + 2t + 3y)(-7)

Read Solution (Total 0)

exam Other Question

561 students, girls are 15 more than twice the number of boys.
how many girls are there and how many boys. this is not from a text book. I did it this way.
2x+15=561 but my answer did not seem right, there is something I am missing. Can someone help me on the following?

I need to find the slope and y-intercept:

x = -9

Thanks,
Ashley