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3 years ago

9

Jamar is four times as old as Josh. In 20 years he will be twice as old as Josh. How old is Jamar?

1 answer:

Juliette [100K]3 years ago

5 0

Simultaneous equations
Jamar=J
Josh=j
4J=j
20+J=2j
Then
4J=j
-4 (J)=-4(2j-20)
So
0=-7j+80
7j=80
j=80÷7

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3 years ago

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$x_{1,\:2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

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$=\sqrt{10^2-4\cdot \:2\cdot \:5}$

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$=\sqrt{100-40}$

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$=\sqrt{60}$

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$=2\cdot \:30$

$30\:\mathrm{divides\:by}\:2\quad \:30=15\cdot \:2$

$=2\cdot \:2\cdot \:15$

$15\:\mathrm{divides\:by}\:3\quad \:15=5\cdot \:3$

$=2\cdot \:2\cdot \:3\cdot \:5$

$2,\:3,\:5\mathrm{\:are\:all\:prime\:numbers,\:therefore\:no\:further\:factorization\:is\:possible}$

$=2\cdot \:2\cdot \:3\cdot \:5$

$=2^2\cdot \:3\cdot \:5$

$=\sqrt{2^2\cdot \:3\cdot \:5}$

Apply Radical Rule:

$=\sqrt{2^2}\sqrt{3\cdot \:5}$

Apply Radical Rule:

$\sqrt{2^2}=2$

$=2\sqrt{3\cdot \:5}$

$\mathrm{Refine}$

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$\mathrm{Separate\:the\:solutions}$

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Apply Rule -(-a)=a

$=\frac{10+2\sqrt{15}}{2\cdot \:2}$

$\mathrm{Multiply\:the\:numbers:}\:2\cdot \:2=4$

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$=\frac{2\left(5+\sqrt{15}\right)}{4}$

$\mathrm{Cancel\:the\:common\:factor:}\:2$

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$\frac{-\left(-10\right)-2\sqrt{15}}{2\cdot \:2}$

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$\mathrm{Cancel\:the\:common\:factor:}\:2$

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3 years ago

What is the surface area of the triangular prism?

TiliK225 [7]

Answer:

<h2>2,376 ft²</h2><h2 />

Step-by-step explanation:

surface area = bh + L(s1 + s2 + s3)

where b = 24 ft.

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s2 = 15 ft.

s3 = 24 ft.

L = 40 ft.

<u>plugin values into the formula:</u>

A = 24*9 + 40(15 + 15 + 24)

= 216 + 40(54)

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7 0

3 years ago