In this system of equations, I'll do elimination. Ok, so what we are trying to do is to eliminate a variable, but we can't. So since -2y is negative, and y has a coefficient of 1 and is positive, let's multiply the first whole equation by 2.
2 times (3x+y=11) is 6x+2y=22. (I just used distributive property.) Now let's add from left to right.
6x plus x is 7x, 2y plus -2y is 0, and 22 plus 6 is 28. Now we have this simple equation, 7x=28. We can simply divide each side by 7, to get x as 4. So x=4 in this set of equations. Now all we need to do is plug x in the equation then solve for y. For this system of equations, I'll use the first equation, because it is easier. So I'll plug x as 4 into the equation to get 12+y=11. Now we can simply solve for y. 11-12 is -1, so y must equal -1. So y=-1. Therefore, x=4 and y=-1. Hope I helped.
Answer:
The last one
Step-by-step explanation:
68/5 - 22/5 = 46/5 = 9 1/5
Answer:
Market price $400
Cost price $300
Step-by-step explanation:
MP: market price
CP: cost price
1. (MP x 0.9) - CP = 60
CP = 0.9MP - 60
2. MP - CP = 100
CP = MP - 100
0.9MP - 60 = MP - 100
MP - 0.9MP = 100 - 60
0.1MP = 40
MP = 400
Cost price = MP - 100 = 400 - 100 = 300
What number is y equal to
Answer:
V = 82,406.16 cm³
Step-by-step explanation:
Volume of a sphere
V = 4πr³/3
V = 4•3.14•27³/3
V = 247,218.48/3
V = 82,406.16 cm³
