3x + 5y = 7 4x + 3y = 2 Both x and y have to be the same numbers!

Mathematics

2 answers:

Valentin [98]3 years ago

7 0

I think there was a something wrong in you question because the answer does not be the same as you want

Black_prince [1.1K]3 years ago

4 0

Simultaneous Equations:
(3x + 5y = 7)×(-3)
(4x + 3y = 2)×(5)

-9x - 15y = -21
20x+15y =10 (-15y and and+15y cancels out)

11x = -11
$\frac{11x}{11}$ = $\frac{-11}{11}$ (11 and 11 cancels out)
x= -1
substitute the x we found into either original expressions

3(-1) + 5y = 7
-3 + 5y = 7
+3 -3+ 5y = 7+ 3
5y = 10
$\frac{5y}{5}$ = $\frac{10}{5}$ (5 and 5 cancels out)
y=2
Check it!
4(-1)+3(2) = 2
-4 + 6 = 2
2 = 2

3(-1) + 5(2) = 7
-3 + 10 = 7
7 = 7

x= -1
y= 2

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The area of Sahara desert is 7 times the area of the Gobi Desert. If the sum of their areas is 4,000,000 square miles, find the

ryzh [129]

X=area of Sahara.
y=area of the Gobi Desert.
We suggest this system equations:
x+y=4000000
x=7y
solve by susbstitution method.
(7y)+y=4,000,000
8y=4,000,000
y=4,000,000 / 8=500,000

x=7y
x=7(500,000)=3,500,000

The area of Sahara=3,500,00 miles².
The area of the Gobi Desert=500,000 miles²

To check:
Te sum of their areas is : 3,500,000 miles²+500,000 miles²=4,000,000 miles²
Te area of sahara (3,500,000 miles²) is 7 times the area of the Gobi Desert (7*500,000 miles²=3,500,000 miles²).

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2 years ago

Solve for a. Show your work (ALL steps must be shown): -2(a-3)=12

irga5000 [103]

Answer

a= -6

Step-by-step explanation:

-2(a-3)=12

1.) -2(a)= -2a

2) -2(-3)= 6

3) -2a+6=12

-6 -6

4) -2a/-2 = 12/-2

a = -6

3 0

3 years ago

Solve for x. Sqrt8 (Sqrt2 - x) = 11

Alexus [3.1K]

Answer: $\frac{-7\sqrt{2} }{4}$

Step-by-step explanation:

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