Solve the system of equations by substitution
2x+y=10
y=5x-11

(c) the diagram shows the first three shapes of a matchsticks arrangement.first shape = 3second shape = 5third shape = 7given m represents the number of matchstick used to arrange the n'th shape.(i) write a formula to represent the relation between m and n. express m as the subjectof the formula.(ii) 19 matchsticks are used to make the p'th shape. find the value of p.

Sole the equation 6n + 9 = -3n - 21 - 6 for n

Tanyss's house has 25 windows. her brother has washed 22 of the windows. what percent of the windows has her brother washed?