Answer:
= 3a + 7b - 8c
Step-by-step explanation:
In addition of algebraic expressions while adding algebraic expressions we collect the like terms and add them. The sum of several like terms is the like term whose coefficient is the sum of the coefficients of these like terms.
Horizontal Method: In this method, all expressions are written in a horizontal line and then the terms are arranged to collect all the groups of like terms and then added.
(6a + 8b - 7c) + (2b + c - 4a) + (a - 3b - 2c)
= 6a + 8b - 7c + 2b + c - 4a + a - 3b - 2c
Arrange the like terms together, then add.
Thus, the required addition
= 6a - 4a + a + 8b + 2b - 3b - 7c + c - 2c
= 3a + 7b - 8c
Column Method: In this method each expression is written in a separate row such that there like terms are arranged one below the other in a column. Then the addition of terms is done column wise.
6a + 8b - 7c
- 4a + 2b + c
a - 3b - 2c
3a + 7b - 8c
= 3a + 7b - 8c
Answer:
9
Step-by-step explanation:
Rotational symmetry is when a shape has the same orientation after being rotated.
For example, an equilateral triangle rotated 120° will line back up with itself. A square rotated 90° will also return to its original orientation. Same with a pentagon rotated 72°.
Basically, an n-gon rotated by a multiple of 360°/n will return to its original position.
θ = k 360°/n
For the first rotation:
160° = k 360°/n
160 / 360 = k / n
4/9 = k/n
For the second rotation:
120° = k 360°/n
120 / 360 = k / n
1/3 = k/n
For the third rotation:
80° = k 360°/n
80 / 360 = k / n
2/9 = k/n
For the fourth rotation:
280° = k 360°/n
280 / 360 = k / n
7/9 = k/n
The total rotation angle is -160°.
160 = k 360/n
160 / 360 = k / n
4/9 = k/n
Comparing the denominators, n must be the smallest multiple of 3 and 9. Therefore, n = 9.
2.5/0.2=12.5
2.5 times 12.5=31.25
The actual height of the building is 31.25 cm
the answer would be A. because two negatives equal a positive
Answer:
Step-by-step explanation:
995 2 = 990025
Thia is the correct answer
