X − 4y = 7
5x + 9y = 6
5x − 20y = 35 //1st * 5
5x + 9y = 6
5x +9y - 5x + 20y = 6 - 35 //2nd - 1st
5x + 9y = 6
29y=-29
5x=6-9y
y=-1 //1st : 29
5x=6-9*(-1)
y=-1
x=15:5 //2nd : 5
y=-1
x=3
check:
for x=3 and y=-1 there is:
x − 4y = 7 is 3 − 4*(-1) = 7 is 7=7 ok
5x + 9y = 6 is 15-9=6 is 6=6 ok
answer: (3;-1) represents the solution.
Two other examples of linear relationships are changes of units and finding the total cost for buying a given item x times.
<h3>
Other examples of linear relationships?</h3>
Two examples of linear relationships that are useful are:
Changes of units:
These ones are used to change between units that measure the same thing. For example, between kilometers and meters.
We know that:
1km = 1000m
So if we have a distance in kilometers x, the distance in meters y is given by:
y = 1000*x
This is a linear relationship.
Another example can be for costs, if we know that a single item costs a given quantity, let's say "a", then if we buy x of these items the total cost will be:
y = a*x
This is a linear relationship.
So linear relationships appear a lot in our life, and is really important to learn how to work with them.
If you want to learn more about linear relationships, you can read:
brainly.com/question/4025726
The answer would be 234. You will multiply 28 by 9 and minus 18.
6 acts as the base. 15 acts as the height, because it extends from the base to meet vertex opposite the base at a 90° angle.
General formula for triangle area
a = 1/2 × b × h
plug in the numbers
a = 1/2 × 6 × 15
a = 90/2
a = 45
The area of the triangle is 45 units²
2.1 squared is 4.41, 4.41 times 3.14 is 13.84, 13.84 times 4/3 is 18.46.
your answer is 18.46 cm3
