90 cookies will be needed for 30 students
Answer:
=5×12÷[-12÷{15+(-9)}]
=5×12÷[-12÷6]
=5×12÷(-2)
=-30
Step-by-step explanation:
Subtraction doesn't mix with mult. or div. Are you sure you've copied this problem down correctly?
"decrease an amount (x) by 19" would be x - 19 (NO multiplication here)
Since 6x - 44 and 88 degrees are the same (exterior angles), we can start off with the first equation, 6x - 44 = 88
6x - 44 = 88
+44 +44
6x = 132
÷6 ÷6
x = 22
same with the second problem (exterior angles are equal):
equation:
15x + 6 = 9x + 54
-6 -6
15x = 9x + 48
-9x -9x
6x = 48
÷6 ÷6
x = 8
Hope this helped! :D
