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Need help please and thank you. 1. Solve. 8x^2+5=35. Round to the nearest hundredth. Enter your answers in the boxes. The solutions are approximately and . 2. Solve. 0=x^2+14x+40 Enter your answers in the boxes. The solutions are and .

User Shuvro
by
5.6k points

2 Answers

6 votes

Answer: 1.94 and -1.94 (just took the test, got 100%)

User AgostinoX
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5.3k points
5 votes

Answer:

Part 1) The solutions are approximately
x=1.94 and
x=-1.94

Part 2) The solutions are
x=-4 and
x=-10

Explanation:

Part 1)

in this problem we have


8x^(2) +5=35


8x^(2)=35-5


8x^(2)=30


x^(2)=30/8

square root both sides


x=(+/-)√((30/8))\\ \\x=(+/-)1.94

The solutions are
x=1.94 and
x=-1.94

Part 2)

we know that

The formula to solve a quadratic equation of the form
ax^(2) +bx+c=0 is equal to


x=\frac{-b(+/-)\sqrt{b^(2)-4ac}} {2a}

in this problem we have


0=x^(2) +14x+40

so


a=1\\b=14\\c=40

substitute in the formula


x=\frac{-14(+/-)\sqrt{14^(2)-4(1)(40)}} {2(1)}


x=\frac{-14(+/-)√(36)} {2}


x=\frac{-14(+/-)6} {2}


x=\frac{-14(+)6} {2}=-4


x=\frac{-14(-)6} {2}=-10

The solutions are
x=-4 and
x=-10