Evaluate 7 to the power of 2 pls help

Regular price is $77.00 and the discount is 5% find the sale price

Sundar used linear combination to solve the system of equations shown. he did so by multiplying the first equation by 5 and the second equation by another number to eliminate the y-terms. what number did sundar multiply the second equation by? 2x+9y=41 3x+5y=36

Complete the solution of the equation. find the value of y when x equals to 28 x+3y=28