1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Vadim26 [7]
2 years ago
13

I need help with this question

Mathematics
1 answer:
Makovka662 [10]2 years ago
6 0

Answer: b=7

Step-by-step explanation:

6b+7+7b-8=90

6b+7b+7-8=90

13b-1=90

13b=91

b=7

You might be interested in
Is V <br> 5 rational or irrational
madreJ [45]

Answer:

it's a whole number

Step-by-step explanation:

it's a whole number

4 0
3 years ago
The sum of the sequence of 685+678+671+664+...+6
lukranit [14]

Answer:

Sum of the sequence (Sn) = 33,859

Step-by-step explanation:

Given:

Sequence = 685+678+671+664+...+6

Find:

Sum of the sequence (Sn)

Computation:

a = 685

d = 678 - 985 = -7

an = 6

an = a+(n-1)d

6 = 685+(n-1)(-7)

-679 = (n-1)(-7)

97 = n-1

n = 98

So,

Sum of the sequence (Sn) = (n/2)[a+an]

Sum of the sequence (Sn) = (98/2)[685+6]

Sum of the sequence (Sn) = (49)(691)

Sum of the sequence (Sn) = 33,859

3 0
4 years ago
Solve the system by using a matrix equation (Picture provided)
Katyanochek1 [597]

Answer:

Option b is correct (8,13).

Step-by-step explanation:

7x - 4y = 4

10x - 6y =2

it can be represented in matrix form as\left[\begin{array}{cc}7&-4\\10&-6\end{array}\right] \left[\begin{array}{c}x\\y\end{array}\right] = \left[\begin{array}{c}4\\2\end{array}\right]

A= \left[\begin{array}{cc}7&-4\\10&-6\end{array}\right]

X= \left[\begin{array}{c}x\\y\end{array}\right]

B= \left[\begin{array}{c}4\\2\end{array}\right]

i.e, AX=B

or X= A⁻¹ B

A⁻¹ = 1/|A| * Adj A

determinant of A = |A|= (7*-6) - (-4*10)

                                    = (-42)-(-40)

                                    = (-42) + 40 = -2

so, |A| = -2

Adj A=  \left[\begin{array}{cc}-6&4\\-10&7\end{array}\right]

A⁻¹ =  \left[\begin{array}{cc}-6&4\\-10&7\end{array}\right]/ -2

A⁻¹ =  \left[\begin{array}{cc}3&-2\\5&-7/2\end{array}\right]

X= A⁻¹ B

X=  \left[\begin{array}{cc}3&-2\\5&-7/2\end{array}\right] *\left[\begin{array}{c}4\\2\end{array}\right]

X= \left[\begin{array}{c}(3*4) + (-2*2)\\(5*4) + (-7/2*2)\end{array}\right]

X= \left[\begin{array}{c}12-4\\20-7\end{array}\right]

X= \left[\begin{array}{c}8\\13\end{array}\right]

x= 8, y= 13

solution set= (8,13).

Option b is correct.

3 0
3 years ago
If m∠2 = 23° and m∠3 = 68°, what is m∠1
Harrizon [31]

Answer:

if this is a triangle it is 89º

Step-by-step explanation:

because all the angles in a triangle add up to 180

5 0
3 years ago
Lightning electronics changes $9.98 plus 0.75 per pound to ship electronics purchases. Write and solve an equation to find the w
Blizzard [7]

Answer: 11 pounds

Step-by-step explanation:

x : # of pounds an electronic is

9.98 + 0.75x : total cost of shipping an electronic that is "x" pounds

9.98 + 0.75x = 18.23

0.75x = 8.25

x = 11 pounds

4 0
3 years ago
Other questions:
  • At last month's trivia competition, 20 questions were about history and geography, and the other 35 questions were about pop cul
    15·1 answer
  • Eight thousandths of thirty five million
    15·1 answer
  • Find the equation of the line that has a slope of -3 and passes through (4, 4)
    13·1 answer
  • How Do I Right this in as a tath problem
    7·1 answer
  • If a triangle has a base of 5 cm and a height of 6 cm what’s it’s area?
    7·1 answer
  • tickets to the country fair cost $8 each. Seventy people bought their tickets at the gate. The revenue ticket sales was $ 2,560.
    8·1 answer
  • Through the point (3,1.2) that has an y intercept of 3
    11·1 answer
  • he heights of young women aged 20 to 29 follow approximately the N(64, 2.7) distribution. Young men the same age have heights di
    6·1 answer
  • POINTSS GIVEAWAY!!!!!!!!!!! WHOEVER GETS THEM, YAYYY AND FOR THOSE WHO DONT I HOPE BOTH SIDES OF YOUR PILLOW ARE COOL TONIGHT, R
    8·2 answers
  • The radius of the base of a right circular cone is 4 in., and its slant height is 15 in. If the radius and the slant height are
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!