Answer:
Options B and D are true.
Step-by-step explanation:
See the diagram attached.
Line a and b are parallel and line c is not parallel to them.
There is a transverse line and this line forms the angles 1 to 12.
Now, option A gives ∠ 8 + ∠ 10 = 180° which can not be true as line c is not parallel to line b.
Option B gives ∠4 + ∠ 6 = 180° which is true because line a is parallel to line b and ∠ 4 and ∠ 6 are interior supplementary angles.
Option C gives ∠ 1 + ∠ 11 = 180° which can not be true as line c is not parallel to line a.
Option D gives ∠3 + ∠ 5 = 180° which is true because line a is parallel to line b and ∠ 3 and ∠ 5 are interior supplementary angles.
Therefore, options B and D are true. (Answer)
Step-by-step explanation:
by which method defination method, prime factorization or division method
Let x be the number of pounds of the $1.35 beans. The cost of those beans is $1.35 * x, or 1.35x.
<span>Let y be the number of pounds of the $1.05 beans. The cost of those beans is $1.05 * y, or 1.05y. </span>
<span>We know that 120 pounds of the mix sells for $1.15/pound, for a total of 120 * 1.15 = $138. </span>
<span>x + y = 120 </span>
<span>1.35(x) + (1.05)y = 138 </span>
<span>We can rewrite the first as </span>
<span>x = -y + 120 </span>
<span>Now we can substitute (-y + 120) in for (x) in the second equation, because we just proved they're equal. </span>
<span>1.35(x) + 1.05(y) = 138 </span>
<span>1.35(-y + 120) + 1.05y = 138 </span>
<span>-1.35y + 162 + 1.05y = 138 </span>
<span>-0.3y + 162 = 138 </span>
<span>-0.3y = -24 </span>
<span>y = 80 </span>
<span>And since x + y = 120, that means x = 40. </span>
<span>Check: </span>
<span>40 pounds of x at $1.35 costs 40 * 1.35, or $54. </span>
<span>80 pounds of y at $1.05 costs 80 * 1.05, or $84. </span>
<span>Do those add up to our target total, according to the question, of 120 * 1.15 = $138? </span>
Answer:
a: no solutions
b: (2, 3)
Step-by-step explanation:
a:
In both equations, the slope of x is the same, but the y-intercept is not, which means they are parallel. Therefore, this system of equations has no solutions.
b:
Since both of the equations are equal to y, we can set them equal to each other:
We can solve by factoring (by finding a number that multiplies to 4 and adds up to -4):
(x-2)^2 = 0
x = 2
Now, to find y, plug-in x to any of the equations:
y = 2*2-1 = 3
Therefore, the solution to this system of equation is (2, 3)
I hope this helped.
First term ,a=4 , common difference =4-7=-3, n =50
sum of first 50terms= (50/2)[2×4+(50-1)(-3)]
=25×[8+49]×-3
=25×57×-3
=25× -171
= -42925
derivation of the formula for the sum of n terms
Progression, S
S=a1+a2+a3+a4+...+an
S=a1+(a1+d)+(a1+2d)+(a1+3d)+...+[a1+(n−1)d] → Equation (1)
S=an+an−1+an−2+an−3+...+a1
S=an+(an−d)+(an−2d)+(an−3d)+...+[an−(n−1)d] → Equation (2)
Add Equations (1) and (2)
2S=(a1+an)+(a1+an)+(a1+an)+(a1+an)+...+(a1+an)
2S=n(a1+an)
S=n/2(a1+an)
Substitute an = a1 + (n - 1)d to the above equation, we have
S=n/2{a1+[a1+(n−1)d]}
S=n/2[2a1+(n−1)d]
