Answer:
x^2 -10x+2
Step-by-step explanation:
(3x^2 - 11x - 4) – (x – 2) (2x + 3)
FOIL
(3x^2 - 11x - 4) – (2x^2-4x+3x-6)
Combine like terms
(3x^2 - 11x - 4) – (2x^2 -x-6)
Distribute the minus sign
3x^2 - 11x - 4 – 2x^2 +x+6
Combine like terms
x^2 -10x+2
I’m not sure about number 1 but the answer for number 2 is
-4 1/2, -4.2, -4, ,0, 4
The first thing you want to do is plug in x and y into both equations:
a(3) + b(4) = 4
b(3) + a(4) = 8
rearrange to line up a’s and b’s
3a + 4b = 4
4a + 3b = 8
now you want to choose a or b and multiply each equation by a number to make them have the same amount of a’s or b’s.
4(3a + 4b = 4) = 12a + 16b = 16
3(4a + 3b = 8) = 12a + 9b = 24
Now we subtract the bottom equation from the top and solve for b:
12a + 16b - (12a + 9b) = 16 - 24
7b = -8
b = -8/7
Now we plug back in for b to one of the original equations:
3a + 4(-8/7) = 4
3a + (-32/7) = 4
3a - (32/7) = 4
3a = 4 + (32/7)
3a = (28/7) + (32/7)
3a = 60/7
a = (60/7)/3 = 20/7.
Finally, plug a and b in together to double check using the second equation.
4a + 3b = 8
4(20/7) + 3(-8/7) = ?
(80/7) - (24/7) = ?
56/7 = 8.
Answer:
0.375
Step-by-step explanation:
4 years apart if he is 20 years old
