How to find the y intercept when given the slope and a point?

The actual length of side t is 0.045 cm. use the scale drawing to find the actual side length of w. a) 0.06 cm b) 0.075 cm c) 0.45 cm d) 0.75 cm

The class wants to raise a total of $750.if they receive a profit of $1.25 from each candybar sold, how many bars must they sell to reachtheir goal

When i add money am i supposed to make it like this 7+12 or 7.00+12.00 because i got 19 dollars for my answer