Integral of sqrt(81-x^2)dx using the substitution of x=9sint

Which number produces a rationale number when multiplied by 1/5

In the diagram, the ratios of two pairs of corresponding sides are equal to prove that almn - axyz by the sas similarity theorem, it also needs to be shown that x 6 z un z zz un = 2x zləzz lezy

Write an equation of the line that passes through 9,2 and is parallel to the line y=5/3x+9