3y=8x
Explanation:
If y varies directly with x then
y=c⋅x for some constant of variation c
If (x,y)=(14,23) is a solution to this equation, then
23=c⋅14
→c=23⋅41=83
So
y=83x
or (clearing the fraction)
3y=8x
suppose 4:4:7 be 4x, 4x, 7x
or, 15x = 180°
or, X = 180/15
or, X = 12
therefore,
4x = 4x12= 48
4x= 4x12= 48
7x= 7x12= 84
so if you plus all of them you get 180
Answer:
A
Step-by-step explanation:
An excluded value is any value of x that makes the denominator of the rational expression zero as this would make the expression undefined.
For expression A
The denominator will be zero when x² - 4 = 0
x² - 4 is a difference of squares, thus
(x - 2)(x + 2) = 0
x - 2 = 0 ⇒ x = 2
x + 2 = 0 ⇒ x = - 2
The excluded values of x are x = ± 2 ⇒ A
Help what ??? I don’t see anything
Step-by-step explanation:
x +2y = 9. .....(1)
x - 2y = 5. .....(2)
from eqn (1)
x + 2y = 9
x = 9 - 2y.
substitute x = 9 - 2y into eqn (2)
9 - 2y - 2y = 5
-4y = 5 - 9
-4y = -4
y = 1
sub y = 1 into eqn (1)
x + 2y = 9
x + 2(1) = 9
x + 2 = 9
x = 9 - 2
x = 7.
(2) x + y = 9 ....(1)
x - 2y = 0 .....(2)
from eqn (2)
x - 2y = 0
x =0 + 2y
substitute x = 2y into eqn (1)
x + y = 9
(2y) + y = 9
3y = 9
y = 3
substitute y = 3 into eqn (2)
x - 2y = 0
x - 2(3) = 0
x - 6 = 0
x = 6.
(3) 2x + 7y = 5. ....(1)
2x + 3y = 9. .....(2)
from eqn (1)
2x + 7y = 5
7y = 5 - 2x
y = (5 - 2x)/7
sub y = (5 - 2x)/7 into eqn (2)
2x + 3y = 9
2x + 3(5 - 2x)/7 = 9
2x + (15 - 6x)/7 = 9
multiply through by 7
14x + 15 - 6x = 63
14x - 6x = 63 - 15
8x = 48
x = 6
sub x = 6 into eqn (1)
2x + 7y = 5
2(6) + 7y = 5
12 + 7y = 5
7y = 5 - 12
7y = -7
y = -1
