Im stupid and dont know meth i mean math***

a rectangle has an area of 42 cm²; the length is 7 cm. find its width.

Bradley hikes 12 miles in 3 hours. in relation to bradley’s hike, which statement describes the expression

Ineed i been stuck on this question since yesterday

Emily is entering a bicycle race for charity. her mother pledges $0.90 for every 0.75 mile she bikes. if emily bikes 18 miles, how much will her mother donate?