You can use gauss's method
n(first number + last number)/2 where n is the number of integers in this case 21 ()
21(0.30 + 0.50)/2
21*0.8/2
21*0.4
8.4
(8 x 40) + (8 X 3)
320+24=344
First let's get rid of the x by multiplying the tip equation by -2
-2 (-6x - 2y = -4)
+
(-12x - 5y = -13)
Distribute
(12x + 4y = 8)
+
(-12x - 5y = -13)
x cancels out and you're left with
-1y = -5
y = 5
Now solving for x, plug in your y into one of the equations
-6x - 2(5) = -4
-6x - 10 = -4
-6x = 6
x = -1
(-1 , 5) is the solution
Answer:
Expanded forms can be written like a sentence or stacked for readability
Step-by-step explanation:
Expanded Form:
5,000 + 300 + 20 + 5 = 5,325
(its like a sentence)
