Achemist needs a 70% solution of tannic acid. how much distilled water must he add to 5 gallons of a 90% solution of acid to obtain the 70% solution?

It says factor each expression 49x-28?

List x1, x2, x3, x4 where xi is the midpoint endpoint of the five equal intervals used to estimate the area under the curve of f(x) between x = 0 and x = 10.

Aright triangle has an area of 21 m2. the dimensions of the triangle are increased by a scale factor of 4. what is the area of the new triangle