A textbook store sold a combined total of 228 biology and physics textbooks in a week. The number of blology textbooks sold was three times the number of physics textbooks sold. How many textbooks of each type were sold?

Step-by-step explanation:

Let us assume p is the number of psychology books and b is the number of biology textbooks.

set up first equation:

we know that the total number of books sold was 393

p+b=393

set up second equation:

we know that there were 79 less biology book sold that psychology so...

p = b + 79

subsitute p in the first equation to solve for b

solve value for p

solution:

we have to construct

∠m nt ≅ ∠p qr

the steps to draw this construction are

step 1: use a compass to draw an arc from point q which intersects the side pq at point a and the side qr at point b.

step 2: draw a segment nt and use the same width of the compass to draw an arc from point n which intersects the segment nt at a point x.

step 3:

step 4: join points n and y using a straightedge.

step 3:

option (d).maintaining the same width of the compass as ab, draw an arc from point x such that it intersects the arc drawn from n in a point y.

to draw   congruent angles , 1. width of compasses while drawing two angles should be same i.e from point at which angle has to be drawn, 2.the distance between the two points where the compass intersects the two sides should be same while drawing any two congruent angles.