The equation 2x-7=15 is like a balance equation. The only difference is that there are 0x's on the right side of an equation, but if it helps; I will put 0x. 2x-7=0x+15. What are you left with if you subtract 0x from both sides? You are left with 2x-7=15. Since the x's were eliminated on the right side, we have to eliminate the units on the left side. Therefore, we must add 7 to both sides. Leaving us with 2x=22. Since we need to know what one x is and not two x, we must divide both sides by 2 leaving us with x=11. =
Now let me further explain. The goal is to figure out what 1x equals. There is no benefit of knowing that 2x-7=15. You MUST attempt to figure out what x is all by itself. There is only one way to get rid of -7, and that is by adding +7. After you do that, you are left with 2x=22. Since x is just a variable, let's think of x as a different variable. Let's use the variable Δ (delta). 2Δ=22. We need to know what Δ is not 2Δ. Therefore we will divide both sides of the equation by 2. This leaves us with Δ=11.
Now let me further explain. The goal is to figure out what 1x equals. There is no benefit of knowing that 2x-7=15. You MUST attempt to figure out what x is all by itself. There is only one way to get rid of -7, and that is by adding +7. After you do that, you are left with 2x=22. Since x is just a variable, let's think of x as a different variable. Let's use the variable Δ (delta). 2Δ=22. We need to know what Δ is not 2Δ. Therefore we will divide both sides of the equation by 2. This leaves us with Δ=11.
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