If a + 3b = 13 and a + b = 5, the value of b is?

a. 1
b. 4.5
c. 7
d. 4

Evaluate the expression for the given value of the variable 7a - 4a for a =8

Jalen charges $25.50 for every 3 hours of yard work he does for his neighbors. ralph charges $34 for every 4 hours of work that he does. who charges less? opinions: 1.they charge the same amount 2.jalen 3.ralph

The half-life of a certain material is 0.004 second. approximately how much of a 20-gram sample will be left after 0.016 second? a. 5 grams b. 16 grams c. 0.32 gram d. 1.25 grams