How do I solve this problem?

Step-by-step explanation:

Solution:

Given,

t1( first term ) a = -15

t2( second term ) b = -9

CD(Common Difference) = ?

We know,

CD = b - a

= -9 - ( - 15 )

= -9 + 15

= 6

Now,

t1 = -15

t2 = -9

t3 = -3

t4 = 3

t5 = a + ( n - 1 )CD

= -15 + ( 5 - 1 ) 6

= -15 + 24

= 9

t50 = a + (n - 1 ) CD

= -15 + ( 50 - 1 ) CD

= -15 + 49 × 6

= -15 + 284

= 269

So the sum of t50 is 269.

add all the numbers and check the ones place.

the answer is 486. as the ones place is more than 4, the estimation will be the next 10 ie, 490

-2x + 7 = 7

subtract 7 from both sides.

-2x = 0

divide both sides by -2.

x = 0