Answer:
b=15
Step-by-step explanation:
7(b+1)=2*56 (we cross multiply)
7b+7=112
7b=105
b=15
I am unsure about the very last problem but I can help with the first two
1) (y+1)+4
If we combine the numbers 1 and 4, we get +5 and can isolate the numbers from the variable.
This would give us

2) (6*r)*7
remember that we do not have to explicitly state 6*r
Instead, we can write it as 6r
this helps us get rid of the parentheses
now we can write it as

I hope this helps!:)
Since there are 1000 millilitres in 1 Liter. If we divide 25,000 by 1000 we get an answer of 25 Litres.
Answer:
x=-2,2
Step-by-step explanation:
Since this is a quadratic equation, -2 or 2 could be the possible answer
Steps
$3x^2=12$
$\mathrm{Divide\:both\:sides\:by\:}3$
$\frac{3x^2}{3}=\frac{12}{3}$
$\mathrm{Simplify}$
$x^2=4$
$\mathrm{For\:}x^2=f\left(a\right)\mathrm{\:the\:solutions\:are\:}x=\sqrt{f\left(a\right)},\:\:-\sqrt{f\left(a\right)}$
$x=\sqrt{4},\:x=-\sqrt{4}$
Show Steps
$\sqrt{4}=2$
Show Steps
$-\sqrt{4}=-2$
$x=2,\:x=-2$