Y varies directly with x, and y=24 when x=-15. what is x when y=16? a) 10 b) -22.5 c) -10 d) -25.6
1 answer:
Answer:
c
Step-by-step explanation:
Given that y varies directly with x then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 24 when x = - 15, then
24 = - 15k ( divide both sides by - 15 )
k = = -
= - 1.6 , thus
y = - 1.6x ← equation of variation
When y = 16, then
16 = - 1.6x ( divide both sides by - 1.6 )
x = - 10 → c
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Answer:
B (7, 4 )
Step-by-step explanation:
Given endpoints (x₁, y₁ ) and (x₂, y₂ ) then the midpoint is
[ ,
] ← midpoint formula
let coordinates of B = (x, y ), then using the midpoint formula, equate to each of the coordinates of M, that is
= 2.5 ( multiply both sides by 2 )
- 2 + x = 5 ( add 2 to both sides )
x = 7
= - 1.5 ( multiply both sides by 2 )
- 7 + y = - 3 ( add 7 to both sides )
y = 4
Thus
coordinates of B = (7, 4 )