Use properties of exponents to write an equivalent expression for 5 exponent 4 * 5 exponent -7

How many kilograms of a 5% salt solution and how many kilograms of a 15% salt solution must be mixed together to make 45kg of an 8% salt solution?

The measures of the legs of a right triangle are 15m and 20m . what is the length of the hypotenuse

Cone a has a surface area of 384 ft2 and cone b has a surface area of 96 ft? . what is the ratio of their volume?