The correct answer is A: x=2 and y=-3. Either method would work, but for example, let's use elimination. If you multiply the second equation by 5, you get: 10x +5y = 5. When you add both equations, you can then cross out both y terms. You are left with one equation that reads: 13x=26. Solving for x gives you 2. You can substitute 2 in for x in either equation and you will receive -3 for your y value.
2.45kg
First you calculate the price per kg as follows:
If it’s $20 for 12.25 kg, the price per kg is $20/12.25=$1.63 per kg
If you have $4, you can figure out what weight you can get by taking $4/the price per kg, so $4/$1.63, which is 2.45 kg.
The answer is C an example is 20% of $20 is 4, so you would lose the zero and double the 2 to get 4
Third length =
12-7 = 5
12+7 = 19
Third length can be only in this range
5Means the third length must be greater than 5 and less than 19.
Hope this helps!