There's 9 choices for the first digit and 4 choices for the last digit. The number of choices for the 2nd and 3rd digits is 90 if 2 numbers are different. or 100 if duplicates are allowed.
If duplicates are allowed the answer is 9 * 100 * 4 = 3600 possible numbers.
Answer:
N = 3
Step-by-step explanation:
I don't know what the whole thing above is, but just disregard that.
All it is here is cross multiplication.
So 28N = 21 * 4
Multiply...
28N = 84
And divide each side by 28
N = 3
Answer:
a = -3 b = -5 c = 9
Step-by-step explanation:
A quadratic function is written in the form
ax^2 +bx +c =0
-3x^2-5x+9=0
a = -3 b = -5 c = 9
You can use factors to solve. Determine all the factor pairs of 24, find the two that are two numbers apart.
1, 24 X
2, 12 X
3, 8 X
4, 6 YES!
Algebraic way to solve using Quadratics:
l = 2 + w
A = lw
A = (2 + w)w Substitute (2 + w) for l
24 = (2 + w)w Substitute 24 in for the area
24 = 2w + w^2 Distribute
w^2 + 2w - 24 = 0 Set equal to 0 (put in standard form)
(w + 6) (w - 4) = 0 Factor
w + 6 = 0 and w - 4 = 0 Set each factor equal to 0.
So w= -6 or w = 4 ... -6 makes no sense for a length! So the width must be 4 and the length will be 4 + 2, which is 6.
<span>3x+9=5x+1
Subtract 3x from both sides
9=2x+1
Subtract 1 from both sides
8=2x
Divide 2 on both sides
Final Answer: 4=x</span>
