4. Solve. x² – 81 = 0 (1 point) 0 –9 –9, 9 9

x^2 - 81 = 0. Add 81 to each side.

x^2 = 81. Take the square root of each side.

x = 9, -9

–9, 9

Step-by-step explanation:

x² – 81 = 0

Add 81 to each side

x² – 81+81 = 0+81

x^2 = 81

Take the square root of each side

sqrt(x^2) = ± sqrt(81)

x = ± 9

38.5

step-by-step explanation:

lets say, first number = r

second number = 3r+7

total = 49

(r)+(3r+7)= 49

4r+7 = 49

4r = 42

r = 42/4

r= 10.5

3r+7 = 3(10.5)+7 = 38.5

hope this

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step-by-step explanation: