Please help!! Fill in the blanks and complete the proof.

Y=4x^2+x-1 solve using quadratic formula

The area of square garden is 300m squared. how long is the diagonal?

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