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4 years ago

Find the sum of the first 25 terms of the arithmetic sequence.

Mathematics

1 answer:

Marta_Voda [28]4 years ago

3 0

Answer:

Step-by-step explanation:

$\frac{n}{2}*(a+l)=\frac{25}{2}*(100+220)\\\\=\frac{25}{2}*320=\frac{25*320}{2}\\\\=25*160=4000$

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5. The mapping f: xax² + bx + c defined on the set of real numbers is such that f(0) = -4,f(1)-1 and/(-1)= -5. Find a, b and c.

Marrrta [24]

It looks like you're saying

$f(x) = ax^2 + bx + c$

and you're asked to find $a,b,c$ given $f(0)=-4$ , $f(1)=-1$ , and $f(-1)=-5$ .

Evaluate $f$ at the three given points:

$x=0 \implies f(0) = \boxed{c = -4}$

$x=1 \implies f(1) = -1 = a + b + c \implies a+b = 3$

$x=-1 \implies f(-1) = -5 = a - b + c \implies a - b = -1$

$(a+b) + (a-b) = 3 + (-1) \implies 2a = 2 \implies \boxed{a=2}$

$a-b = -1 \implies \boxed{b=3}$

and the mapping is $f(x) = 2x^2 + 3x - 4$ .

5 0

2 years ago

Help!!!! ASAPpppppp pp

torisob [31]

Answer:

PH/RC

Step-by-step explanation:

The statement of similarity of two triangle shows you which sides are corresponding by listing the vertices of the two triangles is the correct order.

CAR HOP -------> OP/AR

CAR HOP -------> PH/RC

3 0

3 years ago

Which three lengths

Tanya [424]

Answer:

Step-by-step explanation:

You need to add the first 2 numbers and the answer needs to be bigger than the third number and if you add 10 + 5 will be 15 and the third number is 17, so the answer of this is the B

3 0

3 years ago

(1 point) How many ways can you give 9 (identical) apples to your 5 favourite Mathematics lecturers (without any restrictions)?

cricket20 [7]

Answer:

126

Step-by-step explanation:

Total number of apples = 9

Number of favourite Mathematics lecturers = 5

To find number of ways in which 9 (identical) apples can be given to your 5 favourite Mathematics lecturers, find $C(9,5)$