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3 years ago

X=4y-5 2x+3y=23 Solve using the substitution method

Mathematics

1 answer:

jenyasd209 [6]3 years ago

3 0

Answer:

x =7, y = 3

Step-by-step explanation:

We substitute the value of x in terms of y (given) into the equation.

Then we solve for y and plug in the value of y back into the equation for the value of x to find x.

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Please Help...........

klasskru [66]

I believe the answer might be:
x = 28/19

Steps:
Expand
3(5 - x)/2 - 4(3 + 2x)/5

-3x + 15 - 8x + 12
------------ -----------
2 5

Find the LCD for the equation above:
(15-3x) * 5 - (12+8x) * 2
------------- --------------
10 10

Now we combine them since the denominators are equal:
5(-3+15) - 2(8x+12)
--------------------------
10

We expand above:
-31x+51
-----------
10

6 0

2 years ago

(PLEASE HELP ASAP) Marc mixes blue and yellow paint to make his favorite shade of green, which he'll use to paint his house. He

azamat

He can use 14 cans of blue and 20 cans of yellow because blue goes up by 2 and yellow goes up by 3 each time hope this helped (mark brainliest?)

6 0

2 years ago

Solve for x. Round to the nearest tenth, if necessary. P 29° х Q -6.6 R

Margarita [4]

Answer:

The x in this question is 151 degrees

7 0

2 years ago

Read 2 more answers

The population, P(t), of China, in billions, can be approximated by1 P(t)=1.394(1.006)t, where t is the number of years since th

vitfil [10]

Answer:

At the start of 2014, the population was growing at 8.34 million people per year.

At the start of 2015, the population was growing at 8.39 million people per year.

Step-by-step explanation:

To find how fast was the population growing at the start of 2014 and at the start of 2015 we need to take the derivative of the function with respect to t.

The derivative shows by how much the function (the population, in this case) is changing when the variable you're deriving with respect to (time) increases one unit (one year).

We know that the population, P(t), of China, in billions, can be approximated by $P(t)=1.394(1.006)^t$

To find the derivative you need to:

$\frac{d}{dt}\left(1.394\cdot \:1.006^t\right)=\\\\\mathrm{Take\:the\:constant\:out}:\quad \left(a\cdot f\right)'=a\cdot f\:'\\\\1.394\frac{d}{dt}\left(1.006^t\right)\\\\\mathrm{Apply\:the\:derivative\:exponent\:rule}:\quad \frac{d}{dx}\left(a^x\right)=a^x\ln \left(a\right)\\\\1.394\cdot \:1.006^t\ln \left(1.006\right)\\\\\frac{d}{dt}\left(1.394\cdot \:1.006^t\right)=(1.394\cdot \ln \left(1.006\right))\cdot 1.006^t$

To find the population growing at the start of 2014 we say t = 0

$P(t)' = (1.394\cdot \ln \left(1.006\right))\cdot 1.006^t\\P(0)' = (1.394\cdot \ln \left(1.006\right))\cdot 1.006^0\\P(0)' = 0.00833901 \:Billion/year$

To find the population growing at the start of 2015 we say t = 1

$P(t)' = (1.394\cdot \ln \left(1.006\right))\cdot 1.006^t\\P(1)' = (1.394\cdot \ln \left(1.006\right))\cdot 1.006^1\\P(1)' = 0.00838904 \:Billion/year$

To convert billion to million you multiple by 1000

$P(0)' = 0.00833901 \:Billion/year \cdot 1000 = 8.34 \:Million/year \\P(1)' = 0.00838904 \:Billion/year \cdot 1000 = 8.39 \:Million/year$

6 0

2 years ago

A survey of Mr. Thorne’s class shows that 5 out of 8 students will buy lunch today. Based on this result, how many of the 720 st

Ipatiy [6.2K]

450

5:8.
X:720

8x90=720 so multiply 5x90

450

7 0

2 years ago