Answer:
18
Step-by-step explanation:
A two-digit number (xy) will have the value 10x+y. The sum of its digits is x+y.
You want ...
10x +y = 2(x +y)
1 ≤ x ≤ 9
0 ≤ y ≤ 9
The equation can be simplified to ...
8x = y
The only single-digit values for x and y that satisfy the requirements are ...
x = 1, y = 8
The two-digit number of interest is 18.
_____
<em>Check</em>
Its sum of digits is 1+8 = 9. 2×9 = 18.
_____
<em>Comment on the relationship in the problem</em>
Many of us learned our multiplication tables for 9s by remembering that the sum of digits of 9n was 9, and that the leading digit of the product was n-1.
Answer: C
<u>Step-by-step explanation:</u>
f(x) = 2x + 1 ⇒ 2x + 1
<u>- g(x) = -(x² - 7) </u>⇒ <u>-x² + 7 </u>
(f-g)(x) = -x² + 2x + 8
Answer:
2
Step-by-step explanation:
The discriminant is the quantity under the radical in the quadratic formula ...
[tex]x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}[tex]
When that quantity is positive, the square root is real, and the formula gives two real values for x.
Answer: for x=-2
y+6(-2)=11
y+(-12)=11
y=11+12
y=23
for x=0
y+(6*0)=11
y=11
for x=4
y+6(4)=11
y+24=11
y=11-24
y= -13
Step)-by-step explanation:
you just remplace x with his value and solve y
Answer:
Step-by-step explanation:
We are given that
Side of square carpet,s=5 ft
1 foot=12 in
We have to find the maximum error in the area of the carpet by using the linear approximation .
Area of square,A=
Substitute the values
Hence, the maximum error in the area of the carpet=
