Answer:
30
Step-by-step explanation:
(-) (-) = +
Therefore 15 - (-15) = 15 + 15 = 30
Answer:
Step-by-step explanation:
Combine like terms. Like terms have same variable with same power
a) (2xy + 4x) + (15xy - 5x) = <u>2xy + 15xy</u> +<u> 4x - 5x</u>
= 17xy - x
b) (6a + 4b² - 3) + (3b² - 5) = 6a + <u>4b² + 3b²</u> <u>- 3 - 5 </u>
= 6a + 7b² - 8
c) (4x³ - 3x² +4x) + (8x² - 5x ) = 4x³ <u>- 3x² + 8x²</u> <u>+ 4x - 5x</u>
= 4x³ + 5x² - x
d) (7b - 6a + 9y) - (12b + 5a - 2y) =
In subtraction, add the additive inverse of (12b + 5a - 2y)
additive inverse = - 12b - 5a + 2y
(7b - 6a + 9y) - (12b + 5a - 2y) = 7b - 6a + 9y -12b -5a + 2y
= 7b - 12b -6a - 5a + 9y + 2y
= -5b - 11a + 11y
e) (2x² + 7x - 2 + 9y) - (13x + 4x² + 5 - 6y)
Additive inverse of 13x + 4x² + 5 - 6y = -13x + 4x² - 5 + 6y
(2x² + 7x - 2 + 9y) - (13x + 4x² + 5 - 6y)= 2x² + 7x - 2 + 9y -13x - 4x² -5 +6y
= 2x² - 4x² + 7x -13x -2 - 5 + 9y + 6y
= -2x² - 6x - 7 + 15y
Answer:
a; 3.45 * 10^3
b) 2.34 * 10^18
c) 80%
Step-by-step explanation:
a) 3450 in standard form
To write in standard form, we have to place a decimal at the back of the first non-zero number
we have this as ;
3.450
The count of numbers after the decimal point is 3
This will be the power to which 10 will be raised
We have this as;
3.45 * 10^3
b) 234 * 10^16
Let us write 234 in standard form
That will be;
234 = 2.34 * 10^2
So we have ;
2.34 * 10^2 * 10^16
Using the law of indices, we have;
2.34 * 10^(2 + 16) = 2.34 * 10^18
c) From the question, Kuwait is 4/5 of Hong kong’s population
Let Honk Kong’s population be x
4/5 * x = 2.4 million
4x = 5 * 2.4 million
x = 5 * 2.4/4
x = 5 * 0.6
x = 3 million
so writing the population of Kuwait as a percentage of that of Hong kong, we have
2.4/3 * 100%
= 0.8 * 100% = 80%
Step-by-step explanation:
2a. The block of wood has the shape of a rectangular prism. The log has the shape of a cylinder.
2b. Density is mass divided by volume. We know the mass, but we need to find the volume.
Volume of a rectangular prism is:
V = whl
where w is the width, h is the height, and l is the length
V = (18)(10)(8)
V = 1440 in³
So the density is:
d = 46.65 lbs / 1440 in³
d = 0.0324 lb/in³
2c. Volume of a cylinder is:
V = πr²h
where r is radius and h is height.
The circumference is C = 2πr, so r = C / (2π).
r = 25.12 / (2*3.14)
r = 4.00
V = 3.14 (4.00)² (21)
V = 1055.04 in³
So the density is:
d = 39.25 lb / 1055.04 in³
d = 0.0372 lb/in³
2d. The block is less dense than water; the log is more dense than water. So he should make the boat out of the block.