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
MariettaO [177]
3 years ago
5

Solve the system of equations using the substitution method.

Mathematics
1 answer:
Karolina [17]3 years ago
3 0
Substitution is where we first Isolate one of the unknowns, express it in terms of the other unknown, and replace the isolated unknown with the other unknown in another equation. So that each time we only need to deal with one unknown. I think you'll get a better idea here:

First name these 2 equations with 1 and 2.
4x + 5y = 7 (1)
y = 3x + 9 (2)

Since y is already isolated in (2), so we can skip the isolation step and continue to substitute.

Substitute (2) into (1).
4x + 5(3x+9) = 7

Expand.
4x + 15x + 45 = 7

Group.
19x + 45 = 7

Shift +45 to the other side and turn it into -45.

19x = 7 - 45
19x = -38

Shift x19 to the other side, turn it into /19.
X = - 38/19
X = - 2

Now we solved x already, we can just substitute x= - 2 back to equation (2).

y = 3(-2) + 9
y = - 6 + 9
y = 3

So, the answers are
x = - 2
y = 3
You might be interested in
Calculate the number of ways to form a set of three distinct items such that no two of the selected items are in the same row or
Eddi Din [679]

Answer:

1200

Explanation:

Order does not matter, if we said xyz order, it would still not make a difference if it was zyx or yzx hence we use the combination formula:

nCr = n! / r! * (n - r)!

where n= total number of items

r= number of items chosen at a time

Combinations are used when the order of events do not matter in calculating the outcome.

We calculate using the formula:

(30×20×12)÷3!=1200

There are therefore 1200 ways for the three distinct items to not be in same row or column

8 0
3 years ago
Each rectangle on the tile sweater is 6 inches wide and 4 inches high. It took 11 stitches to make 2 inches in width and 21 rows
allsm [11]

Answer:

the answer is 800in

Step-by-step explanation:

3 0
3 years ago
What is the product,in square of the width (x = 18x) and the height (y) of the prism??
a_sh-v [17]
I think the answer to (Y) may be 40 cubic units
6 0
3 years ago
Find a polar equation for the curve given by the cartesian equation y = 2x 2 .
Aleks04 [339]

The first has no r , only 0 since it is a straight line.

4 0
3 years ago
Which of the following are roots of the polynomial function? Check all that apply.
lutik1710 [3]

You know 1 is not a root because the sum of the coeffcients of the equation is 14, not zero.

It is fairly easy to try 3 by synthetic division (see attachment), which tells you that 3 is a root and the remaining quadratic factor is x²-3x-5. The quadratic formula tells you the roots of that factor are

... x = (-b±√(b²-4ac))/(2a) = (3±√29)/2

The appropriate choices are

... C. (3-√29)/2

... D. (3+√29)/2

... F. 3

_____

The quadratic formula tells you the solution to

... ax²+bx+c=0

is x = (-b±√(b²-4ac))/(2a)

We have a=1, b=-3, c=-5.

8 0
3 years ago
Other questions:
  • What is the value of x?<br><br> Enter your answer in the box.
    6·1 answer
  • What number is 100 times larger than 4.8?
    6·2 answers
  • Helen has 2 winter coats, 4 hats and 3 scarves. How many different outfit combinations does Helen have to chose from?
    5·1 answer
  • F(x)=2(x-3)(x-2)(x+1)
    7·1 answer
  • Please help!
    6·2 answers
  • Five starters on a basketball team score 81 points. Could the players have each scored exactly the same number of points? Explai
    15·1 answer
  • Simplify: (4x2 + 21xy – 7y2) + (10x2 + 11y2 – 20).<br> HELP PLEASEEE
    7·1 answer
  • Eduardo enters bike races. He bikes 8 1/2 miles every 1/2 hour. Complete the final step in the table to find how far Eduardo bik
    14·2 answers
  • HELP PLEASE RNNNNNN
    13·1 answer
  • The graph shows the translation, g(x), of the function f(x). What integer represents the horizontal translation of f(x) to g(x)?
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!