Question

factorise 20y^2-245

Answer 1

$20 {y}^{2} - 245 \\ = 5(4 {y}^{2} - 49) \\ = 5(2y - 7)(2y + 7)$

Answer 2

Answer:

Step-by-step explanation:

20y^2=245

y^2=245/20

y=√245/20

y=√5×7×7/2×2×5

y=7/2.