349,555 views
1 vote
1 vote
10x - 8y = 4
-5x + 3y = -9
(please explain step by step I don't understand)​

User Onlyphantom
by
2.4k points

2 Answers

15 votes
15 votes

Answer:

x = 6

y = 7

Explanation:

10x - 8y = 4 ⇒ ( 1 )

-5x + 3y = -9 ⇒ ( 2 )

( 2 ) × 2

2 × ( -5x + 3y = -9 )

-10x + 6y = - 18 ⇒ ( 3 )

( 1 ) + ( 3 )

10x - 8y -10x + 6y = 4 - 18

-2y = - 14

Divide both sides by ( - 2 )

y = 7

Now let us replace y with 7 to find the value of x.

For that, let us use equation ( 1 ).

10x - 8y = 4

10x - 8 × 7 = 4

10x - 56 = 4

10x = 56 + 4

10x = 60

Divide both sides by 10.

x = 6

User Mohammad Fallah
by
3.3k points
16 votes
16 votes

Answer:


  • \boxed{\sf{x=6 \quad y=7}}

Explanation:

Isolate the term of x and y from one side of the equation.

10x-8y=4 and -5+3y=-9

10x-8y=4

x=2(2y+1)/5

Substitute.


\sf{-5*(2(2y+1))/(5)+3y=-9}

Solve.

-y-2=-9

Add by 2 from both sides.

-y-2+2=-9+2

Solve.

-y=-7

Divide by -1 from both sides.

-y/-1=-7/-1

Solve.

Divide the numbers from left to right.

-7/-1=7

y=7

Substitute of y=7.

x=2(2*7+1)/5

PEMDAS stands for:

  • Parenthesis
  • Exponents
  • Multiply
  • Divide
  • Add
  • Subtract

2(2*7+1)/5

Do parenthesis first.

2*7=14

14+1=15

2(15)/5

Multiply.

2*15=30

Divide.

30/5=6

x=6

  • Therefore, the correct answer is x=6 and y=7.

I hope this helps you! Let me know if my answer is wrong or not.

User Emad Salah
by
3.1k points