Answer:
The solution of y² - 1 = 15 is +4 and -4
Step-by-step explanation:
Given
y² - 1 = 15
Our solution goes thus;
Make y² the subject of formula
y² = 15 + 1
Add 15 to 1
y² = 16
Take square roots of both sides
√y² = √16
y = √16
Note that the square root of 16 is either +4 or -4 because +4 * +4 = 16 and -4 * -4 = 16; So, we replace √16 with ±4 which means + or -4
y = ±4
y = +4 and -4
Hence, the solution of y² - 1 = 15 is +4 and -4
