Answer:
Answer is BD
Step-by-step explanation:
Answer:
(-4, 5)
Step-by-step explanation (work shown in attached picture):
1) Since x is already isolated in the first equation, substitute that value for x into the other equation to find y. So, substitute 16-4y for the x in 3x + 4y = 8, then solve for y. This gives us y = 5.
2) Now, substitute that given value for y back into any one of the equations to find x. I chose to do it in the first equation. Substitute 5 for the y in x = 16-4y, then solve for x this time. This gives us x = -4.
Since x = -4 and y = 5, the solution is (-4, 5).
Step-by-step explanation:
We khow the sum and the product of the zeroes of this quadratic polynomial
Here is a trick :
when we khow the sum S and the product P ofvtwo numbers we can find them by solving :
x²-Sx+p=0
here S= -8 and P=12
so:
x²+8x+12=0
Let Δ be the discrminant of this equation: a= 1 , b= 8 and c=12
Δ= 8²-4*12 =16
the zeros are:
(-8-4)/2= -6
(-8+4)/2 = -2
verify:
-6+(-2)= -8
-2*(-6)= 12
now the polynomial quadratic is:
(x+6)(x+2)
Do "42 + 12" Since 7 x 6 is 42 and 4 x 3 is 12.
The value is 1, any number multiplied by 0 is 1