He made a mistake in step #2. It seemed to be a trivial mistake because it involved signs, but it still had a great impact. Since step#2, his solution was already wrong.
Instead of
(-1)²-4(2)(-6) = 1 + 48 = 49
What he did is
(-1)²-4(2)(-6) = -1 + 48 = 47
Well, on every test I have at a school and I believe most schools do this. You need at leasr 80% to pass. But to pass you'd most likely need 80% or 70%. But if you get an 80% you'll be sure to pass! I hope this helps you!
Her total distance (so 265 miles) over the number of hours she drives will give miles per hour.
265miles/5hours=53 miles/hour
Answer:
{d,b}={4,3}
Step-by-step explanation:
[1] 11d + 17b = 95
[2] d + b = 7
Graphic Representation of the Equations :
17b + 11d = 95 b + d = 7
Solve by Substitution :
// Solve equation [2] for the variable b
[2] b = -d + 7
// Plug this in for variable b in equation [1]
[1] 11d + 17•(-d +7) = 95
[1] -6d = -24
// Solve equation [1] for the variable d
[1] 6d = 24
[1] d = 4
// By now we know this much :
d = 4
b = -d+7
// Use the d value to solve for b
b = -(4)+7 = 3
Solution :
{d,b} = {4,3}
