To use the elimination method you need the same variable in each equation to have the same coefficient. If neither variable has the same coefficient in each equation, you need to multiply one or both of the equations by a constant to get the same coefficient.
Step-by-step explanation:
Sum of arithmetic terms = n/2 × [2a + (n - 1)×d], where 'a' is the first term, 'd' is the common difference between two numbers, and 'n' is the number of terms.
this is the same as n/2 × (a1 + an), because
an = a1 + (n-1)×d
so, for the series above :
a or a1 = 2
d = 7, as every new term is the previous term plus 7.
for n
37 = a1 + (n-1)×d = 2 + (n-1)×7
and now solve for n
35 = 7n - 7
42 = 7n
n = 6
so, the sum of all terms is
6/2 × (2+37) = 3×39 = 117
Break it down 61×4=244
74×6=444
Basically, you know a parallelogram has 4 angles which all add up to 360 degrees. (3x+5)+(x+3y)+2x+70=360 degrees. Just solve for x and y
Answer:
Step-by-step explanation:
Now the key here is manipulating the scale:
For 3 every 2cm = 15mi
Divide by 2 so every 1cm = 7.5mi
So if we had 16.27cm then that would equal 16.27 x 7.5 = 122.025mi on the actual scale
Same for 4: if 1/2cm = 20mi
Then multiply times 2 and every 1cm = 40mi
So 11.73cm x 40 = 469.2mi on the actual scale
Hopefully this is right and it helps!
