The shape below is formed from a rectangle measuring 21 cm by 25 cm from which a rectangle of length 8.6 cm has been removed.
Work out the perimeter of the shape.
25 cm
21 cm
9.2 cm​

6n^2-7n-75=0 solve by quadratic formula

How many liters of peroxide should be added to 12 liters of an 8% peroxide solution so that the resulting solution contains 16% peroxide?   original added new amount of peroxide 0.96 liters x 0.96 + x amount of solution 12 liters x 12 + x 0.18 liter 1.14 liters 1.92 liters 2.10 liters

Which of these side lengths could form a triangle a) 2 cm , 2 cm , 4 cm b) 3 cm , 5 cm , 10 cm c) 3 cm , 4 cm , 5 cm d) 4 cm , 8 cm , 15 cm