Answer:
The number is 0.2
Step-by-step explanation:
Write an equation for it:
Say that the number was called x
2(x +8) =16.4
Brain added 8 to the number (x) and then doubled it which is the 2
Times out the brackets 2x + 16 = 16.4
Take away 16 from both sides
2x = 0.4
0.4 / 2 = 0.2
Answer:
x = -1
y = -9
Step-by-step explanation:
<u>A</u><u>d</u><u>d</u><u> </u><u>each linear equation:</u>
Sum: 5x = -5
<u>Divide each side by </u><u>5</u><u>:</u>
Quotient: x = -1.
<u>Substitute x = </u><u>-</u><u>1</u><u> into the </u><u>first</u><u> equation:</u>
4(-1) - y = 5
<u>Solve</u><u>:</u>
-4 - y = 5
<u>Add 4 to both sides of the equation:</u>
-y = 9
y = -9.
<u>Check with the second equation:</u>
-1 + -9 = -10.
Correct.
Answer:
29 and 31 are the only primes.
