Answer:
12
Step-by-step explanation:
4x + 5y = 3 ................ (i)
kx + 15y = 9................(ii)
Dividing eqn (ii) by 3, we get,
k/3 x + 5y = 3.............(iii)
Subtracting eqn (iii) by eqn (i), we get,
-4x - k/3 x = 0
or, -(4 - k/3 )x = 0
or, 4 - k/3 = 0/x
or, 4 - k/3 = 0
or, 4 = k/3
or, k = 4*3
:. k = 12 (Ans)
Answer:
21.005, 21.05, 21.15, 22.009, 22.01
Step-by-step explanation:
Answer:
c + 2d = $7.00
2c + 3d = $12.00
Step-by-step explanation:
Hello!
<u>Let:</u>
- c = # of coffees
- d = # of donuts
1 coffee and 2 donuts cost $7.00
This can be repesented by 1c + 2d = $7.00, or c + 2d = $7.00
2 coffees and 3 donuts cost $12.00
This can be represented by 2c + 3d = $12.00
<u>So, the system is :</u>
c + 2d = $7.00
2c + 3d = $12.00
2x+y=6
y=6-2x and y=x^2-4x+3
The solution occurs when they are equal so we can say y=y which is:
x^2-4x+3=6-2x add 2x to both sides
x^2-2x+3=6 subtract 6 from both sides
x^2-2x-3=0 factor
(x+1)(x-3)=0
So x=-1 and 3, using y=6-2x we find the corresponding y values...
y(-1)=6--2=8, y(3)=6-6=0 so the two solutions are the points:
(-1,8) and (3,0)
90 feet/5 minutes = 18 feet per minute
