All categories

3 years ago

If a-b=10 and a+b=31 what is the value of 3a-2b

Mathematics

1 answer:

Evgesh-ka [11]3 years ago

7 0

a - b = 10

a + b = 31

(a - b) + (a + b) = 10 + 31

2a = 41

a = 41/2

41/2 - b = 10

b = 21/2

3a - 2b = 3(41/2) - 2(21/2) = 81/2

You might be interested in

A 0.311 kg tennis racket moving 30.3 m/s east makes an elastic collision with a 0.0570 kg ball moving 19.2 m/s west. Find the ve

max2010maxim [7]

Answer:

The velocity of the tennis racket after the collision 14.966 m/s.

Step-by-step explanation:

An elastic collision is an encounter between two bodies in which the total kinetic energy of the two bodies remains the same.

So, the total kinetic energy before collision = the total kinetic energy after collision.

For the given problem let the following:

m₁ = mass of tennis racket = 0.311 kg

m₂ = mass of the ball = 0.057 kg

u₁ = velocity of tennis racket before collision = 30.3 m/s

u₂ = velocity of the ball before collision = -19.2 m/s

v₁ = velocity of tennis racket after collision

v₂ = velocity of the ball after collision

Right ⇒east (+) , Left⇒ west (-)

v₁ = [ u₁ * (m₁ - m₂) + u₂ * 2m₂ ]/ (m₁ + m₂)

= ( 30.3 * (0.311 - 0.057) - 19.2 * 2 * 0.057 ) / ( 0.311 + 0.057)

= 14.966 m/s.

So, the velocity of the tennis racket after the collision 14.966 m/s.

5 0

3 years ago

What is the common denominator of y+y-3/3 in the complex fraction y+y-3/3/5/9+2/3y

nordsb [41]

This is the concept of algebra, the denominator of y+(y-3)/3 will be as follows;
the expression y+(y-3)/3 can be written as:
y/1+(y-3)/3
the denominator of the first term is 1 and that of the second denominator is 3, to get the common denominator for both terms we multiply both denominators;
thus the common denominator will be:
3*1=3
thus the our common denominator will be 3:

8 0

3 years ago

Read 2 more answers

Emily put toys into a square box that is 46 centimeters long. How many square centimeters is the bottom of the box?

Sedaia [141]

If the box is a square and the length of one side is 46cm, then the area of the box in square centimeters is 46 * 46 = 2116.
Final Answer:
d. 2116
Hope I helped :)

7 0

3 years ago

An electric company has to track on-time payments and late payments for each customer monthly. It is impossible for a customer t

OLga [1]

Answer:

The probability that a customer pays late each month is P(B) = 0.27

Step-by-step explanation:

Let P( A ) be the probability that the customer pays on time and the value is 0.55

Let P( B ) be the probability that a customer pays late each month

The probability that a customer pays late or on-time each month is P(A u B) and the value is 0.82

The probability that a customer pays on-time and late each month is P(A n B) and the value is zero ( 0 ) given that it is impossible

Now The probability that a customer pays late or on-time each month is mathematically represented as

P(A u B) = P(A) + P(B) - P(A n B)

=> 0.82 = 0.55 + P( B ) - 0

=> P(B) = 0.27

8 0

3 years ago

Find the length of segment GH. 21 12 F

jek_recluse [69]

Answer:

GH = 9

Step-by-step explanation:

FH=FG+GH

21= 12+GH

GH = 21-12 =9

I hope I helped you^_^

6 0

3 years ago