3 years ago

X2 + 8x = 15 help me

Mathematics

2 answers:

dangina [55]3 years ago

5 0

Answer:1.5

Step-by-step explanation:10x=15

x=15/10

x=1.5

svlad2 [7]3 years ago

3 0

Answer:

x₁ = - 4 + √31

x₂ = - 4 - √31

Step-by-step explanation:

x² + 8x = 15

x² + 8x - 15 = 0

x = [- 8 ± √8² - 4×1×(-15)]/(2×1)

x = (-8 ± 2√31)/2

x₁ = (-8 ± 2√31)/2

x₁ = - 4 + √31

x₂ = - 4 - √31

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