Over -7 6
S X
rate of change

If your teacher tells you to do questions 6 through 19 in your math book for homework, how many questions is that

If 30 lb of rice and 30 lb of potatoes cost ? $27.60? , and 20 lb of rice and 12 lb of potatoes cost ? $15.04? , how much will 10 lb of rice and 50 lb of potatoes? cost?

Idon't get undoing if its pass adding and subtracting so can someone ? x-2 over 5 = 18