Answer:
d.
Step-by-step explanation:
if x varies directly as y,
x = ky
8 = 12k
12k = 8
k = 8/ 12
k = 2/3,
x = 2/3 y
now substitute the value of any of the numbers of each pair, and check if it works:
for e.g, find x when y = 15
x = 2/3y
x = 2/3 × 15
x = 10
since you obtain x = 10 when y = 15, the pair is a possible corresponding value of x and y. now do the same for the rest .
ii) x = 2/3y
x = 2/3 × 3, when y = 3
x = 2
hence, this is also a possible pair of x and y values.
iii) x = 2/3y
x = 2/3 × 9 when y = 9
x = 6
again, a possible pair of x and y values.
iv) x = 2/3y
x = 2/3 × 20 when y = 20
x = 40/3
here, when y = 20, x is not 15. it is 40/3.
thus, it can be determined that this is not a possible pair of x and y values.
please try to understand and have a great day!
Answer:
-2a²
Step-by-step explanation:
The question is 2a × -a
This means 2a(-a)
= -2×(a×a)
=-2(a²)
=-2a²
Answer: Ali would need to drive 350 miles for the two plans to cost the same.
Step-by-step explanation:
This question can be solved by creating two equations using the information supplied in the question and then solving these simultaneously.
Let the cost be C.
Let the number of miles be M.
Let the initial payment be i.
Let the rate per mile driven be R.
Plan 1:
C = i+R×M
C = 70+0.60M ... equation 1
Plan 2:
C = i+R×M
C = 0+0.80M
C = 0.80M ...equation 2
Substituting equation 2 into equation 1:
0.80M = 70+0.60M
0.80-0.60M = 70
0.20M = 70
M = 70/0.20
M = 350 miles
Answer:
m∠BCD = 140°
Step-by-step explanation:
ABCD is cyclic quadrilateral. A property of cyclic quadrilateral states that the opposite angles of it sum up to 180°. Here:
m∠A + m∠C =180° and m∠B + m∠D = 180°
So, m∠A + m∠C =180°
m∠A = 40° (given in the question)
40° + m∠C = 180°
m∠C = 180° - 40° = 140°
∴m∠C = m∠BCD = 140°
