book Maths Puzzle Numerical Ability

I cannot figure out how to work this problem: Find the value of k so that the slope of the line is 3/2. (2+k)x+(2-k)y=15 . Any help would be greatly appriciated.

Read Solution (Total 0)

book Other Question

A store advertises an air conditioner on sale for $280. If this is marked down 20%, what was the original price.

Again I tried to use a proportion or multiply 20% x 280 and I do not get the answer in my book. Please help me. When a 100-m building is imploded, about how long does it take for a piece that breaks off from the roof to fall to the ground ?