The second graph is correct. Because the first equation is <= -x-1, it must fall under that line: only the second and fourth graphs do so. The second equation, >=2x+4, means it must fall above that line: only the second and third graphs do so.
Infinite number of solutions. <span />
Answer:
31 is a prime number.
How to tell if a number is prime: estimate the square root. In this case, we know the square root of 31 is between 5 and 6 and it isn’t divisible by either of those. If it is divisible by a number higher than it’s square root, the other factor must be lower. Is it divisible by 4 or 2? no, because it isn’t an even number. It’s not divisible by 3, because there’s a remainder of 1 if you try. You’ve eliminated all numbers less than the square root, so it is prime
Answer:
Since we know that ABCD ~ EFGH, we have the ratios:
EF/AB = GH/CD
=> 0.4/1.2 = x/1.8
=> x = (1.8 . 0.4)/1.2 = 0.6
So x = 0.6