Answer:
0
Step-by-step explanation:
5(x+3) replace x with -3
5(-3+3)
5(0)
0
Answer:
a) 
b) 
Step-by-step explanation:
a) 
1. Distribute the second power (2) outside the first pair of parenthesis:

= 
2. Distribute the third power (3) outside the second pair of parenthesis:

= 
3. Combine like terms:

--------------------------------------------
b) 
1. Factor the number 6 (= 2 · 3):

2. Cancel the common factor (2):

3. Cancel out
in the numerator an denominator:

hope this helps!
Answer:
4 ohms
Step-by-step explanation:
The question is "In two minutes a current of 5 amps develops 1,200 heat units in a wire of 8 ohms resistance. What resistance does a similar wire have, which develops 6,000 heat units with a current of 10 amps in 5 minutes?"
Current, I₁ = 5 A
Heat, Q₁ = 1200 units
Resistance, R₁ = 8 ohms
Time, t₁ = 2 min = 120 s
New heat, Q₂ = 6000 units
Current, I₂ = 10 A
New time, t₂ = 5 min = 300 s
We need to find the new resistance.
Heat developed is given by :


So, the new resistance is 4 ohms.
Answer:
true
Step-by-step explanation:
2(-2)=-4
Let x represent the amount to be added. The total amount of tin will be
15%·20 + 10%·x = 12%·(20+x)
(15%-12%)·20 = (12%-10%)·x
3%·20/2% = x
30 = x
30 pounds of 10% tin must be added to get a 12% mixture.