31 is the answer; this is because to get to the place-holder number “0” you have to add 19 to -19, then after this, you add 12, making the total 31.
Answer:
120 pounds
Step-by-step explanation:
We can use systems of equations to solve this problem. Assuming j is Jim's weight and b is Bob's weight, the equations are:
j + b = 180
b - j = 1/2b
Let's get b - j = 1/2b into standard form (b, then j, then the equal sign, then the constant.)

Now we can solve using the process of elimination.

Now we know how much Bob weighs, for fun, let's find Jim's weight by substituting into the equation.

So Bob weighs 120 pounds and Jim weight 60 pounds.
Hope this helped!
The answer is no it will be less here's why let say the original amount is A then a p% increase will be A(1+p/100))
Now from this amount we decrease it by p% this gives A(1+p/100)(1-p/100). We can simplify this expression some by letting x=p/100 then we have A(1+x)(1-x) but this is equal to A(1-x2). You can see that the value of what's inside the () is always <1 as long as x>0. If we calculate how much the amount changes we have A(1-x2)-A=-Ax2 is always a loss.
This is one of the reasons some people lose money in the stock market. If a stock rises 10% and then drops 10% you have actually lost money but it sounds, on the face of it, like you should be even. +10 and -10 percent.
If we now do the calculation for the 25% up and down we have the final amount is is .9375 which is 1.25*.75. and the change is .9375-1=-.0625. So the net result is down 6.25%
<span>bar graph are good for frequencies.</span>