1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
choli [55]
3 years ago
12

Solve the system by using the technique of ‘elimination’: -2x+5y=-42,7x+2y=30

Mathematics
1 answer:
Gekata [30.6K]3 years ago
3 0

Solve the following system using elimination:

{5 y - 2 x = -42 | (equation 1)

7 x + 2 y = 30 | (equation 2)

Swap equation 1 with equation 2:

{7 x + 2 y = 30 | (equation 1)

-(2 x) + 5 y = -42 | (equation 2)

Add 2/7 × (equation 1) to equation 2:

{7 x + 2 y = 30 | (equation 1)

0 x+(39 y)/7 = (-234)/7 | (equation 2)

Multiply equation 2 by 7/39:

{7 x + 2 y = 30 | (equation 1)

0 x+y = -6 | (equation 2)

Subtract 2 × (equation 2) from equation 1:

{7 x+0 y = 42 | (equation 1)

0 x+y = -6 | (equation 2)

Divide equation 1 by 7:

{x+0 y = 6 | (equation 1)

0 x+y = -6 | (equation 2)

Collect results:

Answer: {x = 6, y = -6

You might be interested in
What is the discriminant of 3x^2 - 10 = -2?
Tatiana [17]
The formula for the discriminant is b^2-4ac. The formula you wote is in the form of 
ax^2+c=0, so first, you need to bring that -2 to the left. When you do that, you get (the original equation would be ax^2+bx+c but you have no bx.)

3x^2-8

So, since there's no b, it would be
b^2-4ac
0^2-4(3)(-8
-12 x -8
96

7 0
3 years ago
What is the Value of x
Ugo [173]

Answer:

x = 11

Step-by-step explanation:

A segment parallel to a side of a triangle cuts off proportional segments on the sides.

48/6 = (3x + 7)/5

8 = (3x + 7)/5

3x + 7 = 40

3x = 33

x = 11

8 0
2 years ago
Can somebody please help me rn answer <br> ASAP
Viefleur [7K]

Step-by-step explanation:

where is the question huh ?

7 0
3 years ago
Can someone help me? :(<br><br>​
aleksandr82 [10.1K]

Answer:

0.037037037037037 i think

Step-by-step explanation:

3 0
3 years ago
Read 2 more answers
Simplify the following expression. -7x²-2+5x+13x² - 15x​
andreev551 [17]

Answer: 2(3x^2-5x-1) or 6x^2-10x-2

Step-by-step explanation: combine like terms, and then factor by grouping :)

8 0
1 year ago
Other questions:
  • Which is the graph of the parent reciprocal function?
    15·2 answers
  • An item costs c dollars and 6% sales tax is charged... You are buying a skateboard that costs $75. What is the cost of the skate
    8·2 answers
  • What is a parallel slope for the line y = 2x + 2?
    13·1 answer
  • Which expressions are equivalent to <br><br> 2 ln a + 2 ln b - ln a?
    11·1 answer
  • I don't understand how to begin this problem
    8·1 answer
  • If x is an odd number, write an expression for the odd number that directly follows x.
    13·1 answer
  • Eight less than 1/3 a number n is -13
    6·2 answers
  • Katyuska selects a playing card at random from the following 6 66 cards: { {left brace 9 99 of hearts, 5 55 of spades, 6 66 of h
    6·1 answer
  • 4) If four times a number, increased by 1, is the same as three times a
    12·1 answer
  • Simplify<br> 1/4(1 - 2/3)* + 1/3<br> Enter your answer in the box as a fraction in simplest form
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!