We basically have to cancel values on both sides until they are both on common ground.
7 + 3x = 5x + 13
-7 from both sides...
3x = 5x + 6
-5x from both sides...
-2x = 6
/-2 from both sides...
x = -3
Hope this helps!
Since the largest size of one of the dimensions is 10.5, it has to correspond with the long side of the card, the 5 in. side. To find the proportion of the sides, divide 10.5 by 5. Then, multiply the other side of the card by the quotient.
10.5/5 = 2.1
2.1 * 2 = 4.2
4.2in is the shorter side. Your question asks to round to the nearest tenths, the smallest place value of the answer is already the tenths place.
The hundredth is the second number to the right of the decimal point. Also, if the number directly to the right of it is 5 or larger, you will have to round up by one.
23.558 becomes 23.56.
You can use SAS since you know one pair of sides are congruent and AC splits them so those must make those sides equal. And since those sides, DC and BC, are congruent, the angles must be as well. You can use numbers to prove the angles of D and B or just use that when 2 sides and an angle are congruent, the 3rd side must be congruent.