Answer:
x = 9 , y =3
Step-by-step explanation:
-3x + y = 0 ---- 1
2x -2y = -12 -----2
By elimination method:
let's first eliminate x
we can do that by making x equal in both equations
multiply equation 1 by 2 ( because 2 is the coefficient of x in equation 2 and remember we want to equate both equations)
multiply equation 2 by -3 ( because -3 is the coefficient of x in equation 2 and remember we want to equate them both)
-3x + y = 0 ×2
2x -2y = -12 ×-3
-6x + 2y = 0 ----3
-6x + 6y = 36 -----4
subtract equation 4 from 3
that will give
0-4y = -36
which is
-4y = -36
divide both sides by coefficient of y which is-4
(-4y) ÷ (-4) = (-36)÷(-4)
answer : y= 9
substitute 9 for y in equation 1
-3x + y = 0
-3x + 9 = 0
subtract 9 from both sides
-3x +9-9= 0-9
-3x = -9
divide both sides by coefficient of x which is-3
(-3x)÷(-3) = (-9÷-3)
x = 3
Answer: Y- 3
Step-by-step explanation:
Point A prime is 3 units below Point A, as goes for each of the other corresponding point pairs. ( B and B prime, C and C prime)
Answer:
Orinal number of cats= 171
Step-by-step explanation:
Giving the following information:
Decrease in population= 30%
Current population= 120
<u>To calculate the original number of cats, we need to use the following formula:</u>
Orinal number of cats= current population / (1 - decrease)
Orinal number of cats= 120 / (1 - 0.3)
Orinal number of cats= 171
Answer:
140 ways
Step-by-step explanation:
4 x 5 x 7 = 140
Step-by-step answer:
Given:
A triangle
Perimeter = 60 cm
longest side = 4* shortest side (x)
Solution:
longest side = 4x
shortest side = x
third (intermediate side = 60 -x -4x = 60-5x
The triangle inequality specifies that the sum of the two shorter sides must be greater than the longest side to form a triangle. Hence
x + y > 4x
x + 60-5x > 4x
60 - 4x > 4x
8x < 60
x < 60/8 = 7.5, or
x < 7.5
Therefore to form a triangle, x (shortest side) must be less than 7.5 cm.
Examine the options: both 7 and 5 are both less than 7.5 cm.
40, 30 and 25 all have a problem because the longest side (4 times longer) will exceed the perimeter of 60.
Now also examine cases where 4x is NOT the longest side, in which case we need
4x>=y
or
4x >= 60-5x
9x >=60
x >= 6.67
so x=5 will not qualify, because 4x will no longer be the longest side.
The only valid option is x=7 cm
The side lengths for x=7 and x=5 are, respectively,
(7, 25, 28)
5, 20, 35 (in which case, the longest side is no longer 4x=20, so eliminated)
