
Ronn K. answered 06/06/20
I can teach you, whomever you are!
For those who can solve a problem (equation) with one variable, a two-variable equation is a pretty easy step from there.
Let's let the cost of the Table be T. The cost of the Bench is B.
We are told that the two items together cost $842. This becomes the equation T + B = 842.
We are also told that the Table costs $58 less than the Bench. This becomes the equation T = B - 58.
We are being asked the cost of the Bench (B). We can take either of our two equations and rework them into a form that reads B = ___.
Let's take the first one:
T + B = 842
Subtract T from both sides. (An equation will still be true if we do the same operation to both sides).
T + B - T = 842 - T
But since T - T = 0, the equation becomes
B = 842 - T
In order to determine B, we need to "get rid of" that T. We can use the other equation to accomplish that, and put it in the form of T = ___. In fact, it already is: T = B - 58
Now we can substitute this value of T into the first equation, which you remember has become:
B = 842 - T
B = 842 - (B - 58)
or
B = 842 - B + 58
or
B = 900 - B
To "get rid of" the B on the left side, and to end up with an equation which says what B equals, we need to add B to both sides:
B + B = 900 - B + B
or
2B = 900
Divide both sides by 2 to come down to:
2B/2 = 900/2
B = 450. The bench costs $450.
(And by the way, we also know that T = B - 58, or T = $392. So we also know the cost of the table).
If we have time, we check our answers into the two original statements to see if they are true. 1) The table and bench costs $842. $450 + $392 = $842. True. 2) The table costs $58 less than the bench. $450 - $392 = $58. True. We've got the right answer.