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3 years ago

Solve the system by substitution. -8x - y = 30 -2y = x

Mathematics

1 answer:

masya89 [10]3 years ago

4 0

Answer:

Solution: (-4, 2), x= -4 and y =2

Step-by-step explanation:

-8x - y = 30

-2y = x

Substitute for x

-8*(-2y) - y = 30

16y - y = 30

15y = 30

y = 30/15 = 2

Then x = -2y = -2*(2) = -4

Solution: (-4, 2), x= -4 and y =2

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Which of the following represents the zeros of f(x) = 2x3 − 5x2 − 28x + 15?

likoan [24]

$\mathrm{Use\:the\:rational\:root\:theorem}$

$a_0=15,\:\quad a_n=2$

$\mathrm{The\:dividers\:of\:}a_0:\quad 1,\:3,\:5,\:15,\:\quad \mathrm{The\:dividers\:of\:}a_n:\quad 1,\:2$

$\mathrm{Therefore,\:check\:the\:following\:rational\:numbers:\quad }\pm \frac{1,\:3,\:5,\:15}{1,\:2}$

$-\frac{3}{1}\mathrm{\:is\:a\:root\:of\:the\:expression,\:so\:factor\:out\:}x+3$

$\mathrm{Compute\:}\frac{2x^3-5x^2-28x+15}{x+3}\mathrm{\:to\:get\:the\:rest\:of\:the\:eqution:\quad }2x^2-11x+5$

$=\left(x+3\right)\left(2x^2-11x+5\right)$

$Factor: 2x^2-11x+5$

$2x^2-11x+5=\left(2x^2-x\right)+\left(-10x+5\right)$

$=x\left(2x-1\right)-5\left(2x-1\right)$

$2x^3-5x^2-28x+15=\left(x+3\right)\left(x-5\right)\left(2x-1\right)$

$\left(x+3\right)\left(x-5\right)\left(2x-1\right)=0$

$\mathrm{Using\:the\:Zero\:Factor\:Principle:}$

thus zeros of f(x) is

$x=-3,\:x=5,\:x=\frac{1}{2}$

5 0

3 years ago

Read 2 more answers

Three red rods are 2cm longer than two blue rods. Three blue rods are 2cm longer than four red rods. How long is each rod?

nydimaria [60]

Answer:

The length of each red rod is 10 cm and the length of each blue rod is 14 cm

Step-by-step explanation:

Let

x ----> the length of each red rod in centimeters

y ----> the length of each blue rod in centimeters

we know that

$3x=2y+2$ ----> equation A

$3y=4x+2$ ----> equation B

Solve the system by graphing

Remember that the solution of the system of equations is the intersection point both graphs

using a graphing tool

The solution is the point (10,14)

see the attached figure

therefore

The length of each red rod is 10 cm and the length of each blue rod is 14 cm

4 0

4 years ago

Please help you guys

Svetach [21]

Answer:

It should be 21.1

Step-by-step explanation:

5 0

4 years ago

T-2(3-2t)=2t+9 <br>algebra2

nekit [7.7K]

T-2(3-2t)=2t+9
t-6+4t=2t+9
5t-6=2t+9
5t-2t=9+6
3t=15
t=15/3
t=5

5 0

3 years ago

Read 2 more answers

(A(X+13)=132 what is A and what is X???

frosja888 [35]

Answer:

X=132-13A/A, A cannot equal 0

A=132/X+13, X cannot equal -13

5 0

3 years ago