1. 3x² + 12x - 15 = 0
x = <u>-(12) +/- √((12)² - 4(3)(-15))</u>
2(3)
x = <u>-12 +/- √(144 + 180)</u>
6
x = <u>-12 +/- √(324)
</u> 6<u>
</u> x = <u>-12 +/- 18 </u>
6
x = -2 <u>+</u> 3
x = -2 + 3 x = -2 - 3
x = 1 x = -5
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2. 5x² + 11x + 2 = 0
x = <u>-(11) +/- √((11)² - 4(5)(2))</u>
2(5)
x = <u>-11 +/- √(121 - 40)</u>
10
x = <u>-11 +/- √(81)
</u> 10
x = <u>-11 +/- 9</u>
10
x = -1¹/₁₀ <u>+</u> ⁹/₁₀
x = -1¹/₁₀ + ⁹/₁₀ x = -1¹/₁₀ - ⁹/₁₀
x = ¹/₅ x = -2
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3. 2x² - 11x + 14 = 0
x = <u>-(-11) +/- √((-11)² - 4(2)(14))</u>
2(3)
x = <u>11 +/- √(121 - 102)</u>
6
x = <u>11 +/- √(9)</u>
6
x = <u>11 +/- 3</u>
6
x = 1⁵/₆ <u>+</u> ¹/₂
x = 1⁵/₆ + ¹/₂ x = 1⁵/₆ - ¹/₂
x = 2¹/₃ x = 1¹/₃
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4. 2x² - x - 15 = 0
x = <u>-(-1) +/- √((-1)² - 4(2)(-15))</u>
2(2)
x = <u>1 +/- √(1 + 120)</u>
4
x = <u>1 +/- √(121)</u>
4
x = <u>1 +/- 11</u>
4
x = ¹/₄ <u>+</u> 2³/₄
x = ¹/₄ + 2³/₄ x = ¹/₄ - 2³/₄
x = 3 x = 2¹/₂
<u />
Pretty sure it’s D and F because if you set (x-4)=0, x is 4 and if you set (x+7)=0, x is -7
Answer: x=1 1/3
Step-by-step explanation:
Answer:
<u>150</u>
Step-by-step explanation:
So I will shorten Eric, and Bob's names as E, and B.
So the equations are this
B-E = B+E - 240, E as Eric, and B as Bob, and this E+B=9(E-B)
Move the variables and you get
-2E =- 240
Just divide them both by -2
and E=120
So when we know the value of E we can just plug it into the 1st question
120+B=9B+1080
Moves the Variables and numbers to the other side
8B=1200
1200/8= 150
B=150
There is Bob's weight