Step-by-step explanation:
-3x + 7y = 5x + 2y (you subtract the 2y from both sides)
-3× + 5y = 5x (then add 3x to both sides)
5y = 8x (use x = - 5)
5y = 8x - 5 = -40 (both sides are divided by 5)
y = -8
answer is (-5, -8)
(a) 95 = (x+7)*(x-7)
(b) 95 = (x+7)*(x-7)
Expand the brackets:
95 = x² -7x + 7x -49 = x² - 49
Subtract x² from both sides:
95-x² = -49
Subtract 95 from both sides:
-x²=-49-95
-x²= -144
Divide both sides by -1 to get rid of the negative numbers:
-x²/-1=-144/-1
x²=144
Take the square root of 144:
x = ± squareroot of 144
x = 12 or -12
x = 12 because you cannot have a negative age so Trina is 12 years old.
Yes, his estimate is reasonable. But only if Michael is less than 2 years old.
Answer:
491.4 litres
Step-by-step explanation:
(5.4×13)×7 = 491.4
Step-by-step explanation:
A = -7.
B = -8 x-(-6) is the same as x + 6
C = 13
D = 2
E = -3
