answer the questions?
Answers
Answer:
25.Find the 31st term of an A.P. whose 11th term is 38 and 16th term is 73.
GIVEN:-
a11=a+10d =38...(1)
a16=a+15d=73...(2)
solving equations (1)&(2)
d=7 ; a=-32
TO FIND :-
a31 = a+30d
=-32+30(7)
=-32+210
=178
answer is 178
26.The altitude of a triangle is 7cm less than it's base. if the hypotenuse is 13cm, find the other two sides.
let the base of the triangle = x cm
then the altitude of the triangle =(x-7) cm
given hypotenuse of the triangle =13cm
BY USING PYTHAGORAS THEOREM :-
(hypotenuse) ^2 = (base) ^2 +(altitude) ^2
(13)^2 = x^2 + (x-7)^2
169 =2x^2-14x+49
2x^2-14x-120=0
(x-12)(x+5)=0
x=12; -5
length can't be negative hence we chose
x=12cm
altitude =x-7=12-7 =5cm
HOPE IT WILL HELP U!!!!
Step-by-step explanation:
25) (1 )3rd year -300sets,7th year -700sets,so hear they said the production increases by the fixed number of year, then we can say that (d) =100,n=3,
a+(n-1) d= a+(3-1)d=600
a+(7-1)d=700
by subtracting the equation :we get d =25,a=550
so,now they asked the production on the first year:
a=550.
(2)now they asked upto 7years we use sn=n/2(2a+(n-1) d) substitute the values we got before and n =7
ans is 4375 tv sets
or question:
25) they gave us 2 sol, for 11th term is 38,16th term is 73,now we will write in equation first,
a+(10) d=38, a+(15) d =73
by Subtracting the equation :
d=1, a=28, now we will substitute the given values in this equation a+(31-1) d
ans is 68
26) altitude (a) = base -7
by pythogoras theorem,
(13) ²=b²+(b-7) ²
2b-14b-120 =0
so by solving the equation with the help of quadratic equation, we will get the ans b should not be equal to negative