Answer:
620
Step-by-step explanation:
The formula to find the sum of the first n terms of an arithmetic sequence is n(a1 + aN)/2, where n is the number of terms, aN is the last term and a1 is the first term. We do not know the last term, though, so we must find it. The equation for this is an=a1+(n−1)d, where d is the common difference and a1 is the first term, and n is the number of terms. Therefore, the last term, an is, -7+(19)4 = 69.
Finally, we plug it into the first formula, the formula to find the sum, and we get 20*(-7+69)/2, which gives us 620 as our final answer.
Both the first choice and the fourth choice are correct because the sum of supplementary angles is 180°
Answer:
80,60,40
Step-by-step explanation:
The three angles of a triangle add to 180
Multiply the ratio by x
The angles are 4x, 3x, 2x
Add them together
4x+3x+2x = 180
Add like terms
9x = 180
Divide by 9
9x/9 =180/9
x = 20
The angles are 4x = 4(20) = 80
3x= 3(20) = 60
2x= 2(20) = 40
Answer:
Lots of "ifs" here.
A=bh/2 is the formula for the area of a triangle.
A=bh is the formula for the area of a rectangle or a parallelogram.
If the 6 & 4 area the base & height of a rectangle, then (6)(4) = 24 in^2
If the 6 & 10 are the base and height of a triangle, then 1/2(6)(10) = 30 in^2
Step-by-step explanation:
Answer:
<h2>- 2</h2>
Step-by-step explanation:
The slope intercept form of an equation of a line:
m - slope
b - y-intercept
We have the equation of a line in the standard form
Convert to the slope-intercept form:
<em>subtract 4x from both sides</em>
<em>divide both sides by 2</em>
Therefore the slope is equal to -2.
Other method:
If we have the equation of a line in standard form Ax + By = C
or in general form Ax + By + C = 0, then the formula of a slope is
We have A = 4 and B = 2. Substitute:
