The rationals being closed under subtraction means that if we start with two rational numbers and subtract them, we get another rational number. Choice c subtracts two rational numbers but gets the wrong answer, so isn't support for anything. Choice b is rational too because the square root of 4 is 2.
Answer: b
1280, -2560, 5120
Multiply the preceding term by -2 and
Multiple 15 by 6, the answer is 90 square cm
Answer:it is 6,930
Step-by-step explanation:
You have to solve the two equations by eliminating x or y
<span>2x+5y=10 </span>
<span>x-3y=1 </span>
<span>Multiply all terms of second equation by two and subtract from first equation, thus eliminating x </span>
<span>2x+5y-2x+6y=10-2 </span>
<span>11y=8 </span>
<span>y=8/11 </span>
<span>x=3y+1=3* 8/11+1=25/11 </span>
<span>11x+11y= 11*25/11+ 11*8/11 </span>
<span>= 25+8=33</span>
