Question

Which is the solution of the quadratic equation (4y – 3)2 = 72?

Answer 1

Answer:

$y = \frac{3+6\sqrt{2}}{4}\text{ and } y = \frac{3-6\sqrt{2}}{4}$

Step-by-step explanation:

Given quadratic equation,

$(4y-3)^2=72$

$\implies 4y - 3 = \pm \sqrt{72}$   ( Taking root on both sides )

$4y=3 \pm 6\sqrt{2}$     ( Additive property of equality ),

$y = \frac{3 \pm 6\sqrt{2}}{4}$   ( Division property of equality )

$\implies y = \frac{3+6\sqrt{2}}{4}\text{ or }y =\frac{3-6\sqrt{2}}{4}$

Hence, the solution of the given equation is,

$\implies y = \frac{3+6\sqrt{2}}{4}\text{ and }y =\frac{3-6\sqrt{2}}{4}$

Answer 2

Answer:

y = 9.75

Step-by-step explanation:

(4y - 3)2 = 72

Opening the brackets;

8y - 6 = 72

8y = 72 + 6 = 78

y = 78 ÷ 8 = 9.75