B -13 -34i
(7 + 2i)(-3 - 4i)
Take the 7 then times it buy the second bracket 7x(-3-4i) then take 2i from the first bracket and times it with the second bracket 2ix (-3-4i)
Then keep simplifying
Answer:
Value of b =
=1.25.
Step-by-step explanation:
Direct Variation states that a relationship between two variables in which one is a constant multiple of the other.
*if one variable changes the other changes in proportion to the first.
*If a is directly proportional to b i.e,
then it is of the form
a = kb ;where k is constant variation.
Given: a varies directly as b;
then, by definition of direct variation;
we have;
.....[1]
Substitute the value of a =28 and b =7 to solve for k;

Divide both sides by 7 we have;

Simplify:
k =4
now, find b using same method when a =5;
then;
after substituting the value of a = 5 and k=4 in [1] ;

Divide by 4 to both sides we get;

Therefore, the value of b =
=1.25
Answer:
1400
Step-by-step explanation:
67 rounds to 70 because 7 is bigger than 5 so it rounds up. 23 rounds down since 3 is smaller than 5.
So, 70x20=1400