(5a^2 - b^2) - (4a^2 + 3b^2) - (a^2 - 7b^2)

3b²

step-by-step explanation:

(5a² - b²) - (4a² + 3b²) - (a² - 7b²)

= 5a² - b² - 4a² - 3b² - a² + 7b²

= 3b²

3< x< 5

step-by-step explanation:

|x - 4| < 1

there are two solutions, one positive and one negative.   remember to flip the inequality when taking the negative solution

x-4 < 1       x-4 > -1

add 4 to each side

x-4+4 < 1+4       x-4+4 > -1+4

x< 5                 x> 3

3< x< 5

d

step-by-step explanation: