Answer:
square tables
round tables
12
Explanation:
is this really that difficult ?
just think logically.
a square table sits 8 people. that means every square table "stands" for 8 people present.
a round table sits 6 people. so, every round table "stands" for 6 people present.
now, the whole party has 150 people.
that means the sum of all people on all tables is 150.
so, if we count all square tables, we know how many people are sitting at square tables, as each table "stands" for 8 people (we multiply the number of square tables by 8).
similar for the round tables.
so, we say we have x square tables and y round tables.
therefore the equation is
150 = 8×x + 6×y
the variable with the factor 8 must be describing the square tables (due to the reasons above).
that is x.
and the variable with the factor 6 must describe the round tables.
that is y.
now we are told that there are 9 round tables (y=9).
using the equation from above
150 = 8×x + 6×9 = 8×x + 54
96 = 8×x
x = 12
so, we must have 12 square tables to satisfy the condition that we have in total 150 people present.