-7pq^2 and 12p^2q are unlike terms. -7 and 12 are the respective numeria coefficients. Exercise 4.1 1. Identify each of th e following pairs of terms as like terms or unlike terms. a. 3x and 25x c. (1)/(2)abc and 267abc b. -4x^3 and -3x^4 d. 23pq^2 and 67qp^2 2. Identify the terms , like terms.coefficients, and constants in each expression. 3y-9-13y+5 c. 8n-3n-3+n e. -3d+8-d-2 b. 7x+4-11-2x d. 4y+4-6y-5y f. n+3n-9n-1 (Use o In the previ the distribu The distrib 2(x+3) 2(x+3)= The expre is, these e

1.
a. 3x and 25x are like terms because they have the same variable part, x.
b. $$-4x^{3}$$ and $$-3x^{4}$$ are unlike terms because they have different variable parts, $$x^{3}$$ and $$x^{4}$$ .
c. $$\frac {1}{2}abc$$ and 267abc are like terms because they have the same variable part, abc.
d. $$23pq^{2}$$ and $$67qp^{2}$$ are unlike terms because they have different variable parts, $$pq^{2}$$ and $$qp^{2}$$ .

2.
a. In the expression $$3y-9-13y+5$$ , the terms are $$3y$$ , $$-9$$ , $$-13y$$ , and $$5$$ . The like terms are $$3y$$ and $$-13y$$ . The coefficients are 3 and -13. The constants are -9 and 5.
b. In the expression $$7x+4-11-2x$$ , the terms are $$7x$$ , $$4$$ , $$-11$$ , and $$-2x$$ . The like terms are $$7x$$ and $$-2x$$ . The coefficients are 7 and -2. The constants are 4 and -11.
c. In the expression $$8n-3n-3+n$$ , the terms are $$8n$$ , $$-3n$$ , $$-3$$ , and $$n$$ . The like terms are $$8n$$ , $$-3n$$ , and $$n$$ . The coefficients are 8, -3, and 1. The constant is -3.
d. In the expression $$4y+4-6y-5y$$ , the terms are $$4y$$ , $$4$$ , $$-6y$$ , and $$-5y$$ . The like terms are $$4y$$ , $$-6y$$ , and $$-5y$$ . The coefficients are 4, -6, and -5. The constant is 4.
e. In the expression $$-3d+8-d-2$$ , the terms are $$-3d$$ , $$8$$ , $$-d$$ , and $$-2$$ . The like terms are $$-3d$$ and $$-d$$ . The coefficients are -3 and -1. The constants are 8 and -2.
f. In the expression $$n+3n-9n-1$$ , the terms are $$n$$ , $$3n$$ , $$-9n$$ , and $$-1$$ . The like terms are $$n$$ , $$3n$$ , and $$-9n$$ . The coefficients are 1, 3, and -9. The constant is -1.